From 3fc7629b3a693930c25dfcc2684e2afe71dad522 Mon Sep 17 00:00:00 2001
From: "mr. m" <mr.m@tuta.com>
Date: Sat, 3 Jan 2026 15:00:53 +0100
Subject: [PATCH] feat: Make workspace initialization an async process for
 better performance, b=no-bug, c=common, kbs, workspaces

---
 .../browser/preferences/zen-preferences.ftl   |   1 +
 prefs/zen/session-store.yaml                  |   3 +
 prefs/zen/window-sync.yaml                    |   3 +
 .../base/content/zen-commands.inc.xhtml       |   2 +
 .../tabbrowser/content/tabbrowser-js.patch    | 169 ++++++++++--------
 .../BrowserWindowTracker-sys-mjs.patch        |  25 +++
 src/zen/common/modules/ZenCommonUtils.mjs     |  11 ++
 src/zen/common/styles/zen-theme.css           |   4 +-
 src/zen/common/zen-sets.js                    |   3 +
 src/zen/kbs/ZenKeyboardShortcuts.mjs          |  22 ++-
 .../sessionstore/ZenSessionManager.sys.mjs    |  12 +-
 src/zen/workspaces/ZenGradientGenerator.mjs   |  16 +-
 src/zen/workspaces/ZenWorkspace.mjs           |   8 -
 src/zen/workspaces/ZenWorkspaces.mjs          | 120 ++++++-------
 src/zen/workspaces/zen-workspaces.css         |   4 +-
 15 files changed, 232 insertions(+), 171 deletions(-)
 create mode 100644 src/browser/modules/BrowserWindowTracker-sys-mjs.patch

diff --git a/locales/en-US/browser/browser/preferences/zen-preferences.ftl b/locales/en-US/browser/browser/preferences/zen-preferences.ftl
index ab910a806..e4b18d637 100644
--- a/locales/en-US/browser/browser/preferences/zen-preferences.ftl
+++ b/locales/en-US/browser/browser/preferences/zen-preferences.ftl
@@ -353,3 +353,4 @@ zen-devtools-toggle-storage-shortcut = Toggle Storage
 zen-devtools-toggle-dom-shortcut = Toggle DOM
 zen-devtools-toggle-accessibility-shortcut = Toggle Accessibility
 zen-close-all-unpinned-tabs-shortcut = Close All Unpinned Tabs
+zen-new-unsynced-window-shortcut = New Unsynced Window
diff --git a/prefs/zen/session-store.yaml b/prefs/zen/session-store.yaml
index 78989cdd9..73d185eae 100644
--- a/prefs/zen/session-store.yaml
+++ b/prefs/zen/session-store.yaml
@@ -7,3 +7,6 @@
 
 - name: zen.session-store.log
   value: '@IS_TWILIGHT@'
+
+- name: zen.session-store.restore-unsynced-windows
+  value: true
diff --git a/prefs/zen/window-sync.yaml b/prefs/zen/window-sync.yaml
index f3e30f29d..bc30a8e7c 100644
--- a/prefs/zen/window-sync.yaml
+++ b/prefs/zen/window-sync.yaml
@@ -7,3 +7,6 @@
 
 - name: zen.window-sync.log
   value: false
+
+- name: zen.window-sync.prefer-unsynced-windows
+  value: false
diff --git a/src/browser/base/content/zen-commands.inc.xhtml b/src/browser/base/content/zen-commands.inc.xhtml
index 66cfe1c5b..23bc35478 100644
--- a/src/browser/base/content/zen-commands.inc.xhtml
+++ b/src/browser/base/content/zen-commands.inc.xhtml
@@ -61,4 +61,6 @@
 
   <command id="cmd_zenTogglePinTab" />
   <command id="cmd_zenCloseUnpinnedTabs" />
+
+  <command id="cmd_zenNewNavigatorUnsynced" />
 </commandset>
diff --git a/src/browser/components/tabbrowser/content/tabbrowser-js.patch b/src/browser/components/tabbrowser/content/tabbrowser-js.patch
index 6c57d4978..364bc41da 100644
--- a/src/browser/components/tabbrowser/content/tabbrowser-js.patch
+++ b/src/browser/components/tabbrowser/content/tabbrowser-js.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/tabbrowser/content/tabbrowser.js b/browser/components/tabbrowser/content/tabbrowser.js
-index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa1562a1acc3b 100644
+index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..d69787a3a57dcccce8616457d7eca078ef3b1fca 100644
 --- a/browser/components/tabbrowser/content/tabbrowser.js
 +++ b/browser/components/tabbrowser/content/tabbrowser.js
 @@ -386,6 +386,7 @@
@@ -79,7 +79,18 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
      set selectedTab(val) {
        if (
          gSharedTabWarning.willShowSharedTabWarning(val) ||
-@@ -613,6 +665,7 @@
+@@ -534,6 +586,10 @@
+         userContextId = parseInt(tabArgument.getAttribute("usercontextid"), 10);
+       }
+ 
++      if (typeof window._zenStartupUnsyncedUserContextId == 'number') {
++        userContextId = window._zenStartupUnsyncedUserContextId;
++      }
++
+       if (tabArgument && tabArgument.linkedBrowser) {
+         remoteType = tabArgument.linkedBrowser.remoteType;
+         initialBrowsingContextGroupId =
+@@ -613,6 +669,7 @@
        this.tabpanels.appendChild(panel);
  
        let tab = this.tabs[0];
@@ -87,7 +98,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        tab.linkedPanel = uniqueId;
        this._selectedTab = tab;
        this._selectedBrowser = browser;
-@@ -898,13 +951,18 @@
+@@ -898,13 +955,18 @@
        }
  
        this.showTab(aTab);
@@ -107,7 +118,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
  
        aTab.setAttribute("pinned", "true");
        this._updateTabBarForPinnedTabs();
-@@ -917,11 +975,18 @@
+@@ -917,11 +979,18 @@
        }
  
        this.#handleTabMove(aTab, () => {
@@ -127,7 +138,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        });
  
        aTab.style.marginInlineStart = "";
-@@ -1098,6 +1163,9 @@
+@@ -1098,6 +1167,9 @@
  
        let LOCAL_PROTOCOLS = ["chrome:", "about:", "resource:", "data:"];
  
@@ -137,7 +148,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        if (
          aIconURL &&
          !LOCAL_PROTOCOLS.some(protocol => aIconURL.startsWith(protocol))
-@@ -1107,6 +1175,9 @@
+@@ -1107,6 +1179,9 @@
          );
          return;
        }
@@ -147,7 +158,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
  
        let browser = this.getBrowserForTab(aTab);
        browser.mIconURL = aIconURL;
-@@ -1379,7 +1450,6 @@
+@@ -1379,7 +1454,6 @@
  
        // Preview mode should not reset the owner
        if (!this._previewMode && !oldTab.selected) {
@@ -155,7 +166,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        }
  
        let lastRelatedTab = this._lastRelatedTabMap.get(oldTab);
-@@ -1470,6 +1540,7 @@
+@@ -1470,6 +1544,7 @@
        if (!this._previewMode) {
          newTab.recordTimeFromUnloadToReload();
          newTab.updateLastAccessed();
@@ -163,7 +174,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          oldTab.updateLastAccessed();
          // if this is the foreground window, update the last-seen timestamps.
          if (this.ownerGlobal == BrowserWindowTracker.getTopWindow()) {
-@@ -1622,6 +1693,9 @@
+@@ -1622,6 +1697,9 @@
        }
  
        let activeEl = document.activeElement;
@@ -173,7 +184,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        // If focus is on the old tab, move it to the new tab.
        if (activeEl == oldTab) {
          newTab.focus();
-@@ -1945,6 +2019,11 @@
+@@ -1945,6 +2023,11 @@
      }
  
      _setTabLabel(aTab, aLabel, { beforeTabOpen, isContentTitle, isURL } = {}) {
@@ -185,7 +196,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        if (!aLabel || aLabel.includes("about:reader?")) {
          return false;
        }
-@@ -2053,7 +2132,7 @@
+@@ -2053,7 +2136,7 @@
          newIndex = this.selectedTab._tPos + 1;
        }
  
@@ -194,7 +205,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          if (this.isTabGroupLabel(targetTab)) {
            throw new Error(
              "Replacing a tab group label with a tab is not supported"
-@@ -2328,6 +2407,7 @@
+@@ -2328,6 +2411,7 @@
        uriIsAboutBlank,
        userContextId,
        skipLoad,
@@ -202,7 +213,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
      } = {}) {
        let b = document.createXULElement("browser");
        // Use the JSM global to create the permanentKey, so that if the
-@@ -2401,8 +2481,7 @@
+@@ -2401,8 +2485,7 @@
          // we use a different attribute name for this?
          b.setAttribute("name", name);
        }
@@ -212,7 +223,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          b.setAttribute("transparent", "true");
        }
  
-@@ -2567,7 +2646,7 @@
+@@ -2567,7 +2650,7 @@
  
        let panel = this.getPanel(browser);
        let uniqueId = this._generateUniquePanelID();
@@ -221,7 +232,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        aTab.linkedPanel = uniqueId;
  
        // Inject the <browser> into the DOM if necessary.
-@@ -2626,8 +2705,8 @@
+@@ -2626,8 +2709,8 @@
        // If we transitioned from one browser to two browsers, we need to set
        // hasSiblings=false on both the existing browser and the new browser.
        if (this.tabs.length == 2) {
@@ -232,7 +243,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        } else {
          aTab.linkedBrowser.browsingContext.hasSiblings = this.tabs.length > 1;
        }
-@@ -2814,7 +2893,6 @@
+@@ -2814,7 +2897,6 @@
              this.selectedTab = this.addTrustedTab(BROWSER_NEW_TAB_URL, {
                tabIndex: tab._tPos + 1,
                userContextId: tab.userContextId,
@@ -240,7 +251,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
                focusUrlBar: true,
              });
              resolve(this.selectedBrowser);
-@@ -2923,6 +3001,9 @@
+@@ -2923,6 +3005,9 @@
          schemelessInput,
          hasValidUserGestureActivation = false,
          textDirectiveUserActivation = false,
@@ -250,7 +261,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        } = {}
      ) {
        // all callers of addTab that pass a params object need to pass
-@@ -2933,10 +3014,17 @@
+@@ -2933,10 +3018,17 @@
          );
        }
  
@@ -268,7 +279,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        // If we're opening a foreground tab, set the owner by default.
        ownerTab ??= inBackground ? null : this.selectedTab;
  
-@@ -2944,6 +3032,7 @@
+@@ -2944,6 +3036,7 @@
        if (this.selectedTab.owner) {
          this.selectedTab.owner = null;
        }
@@ -276,7 +287,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
  
        // Find the tab that opened this one, if any. This is used for
        // determining positioning, and inherited attributes such as the
-@@ -2996,6 +3085,21 @@
+@@ -2996,6 +3089,21 @@
            noInitialLabel,
            skipBackgroundNotify,
          });
@@ -298,7 +309,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          if (insertTab) {
            // Insert the tab into the tab container in the correct position.
            this.#insertTabAtIndex(t, {
-@@ -3004,6 +3108,7 @@
+@@ -3004,6 +3112,7 @@
              ownerTab,
              openerTab,
              pinned,
@@ -306,7 +317,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
              bulkOrderedOpen,
              tabGroup: tabGroup ?? openerTab?.group,
            });
-@@ -3022,6 +3127,7 @@
+@@ -3022,6 +3131,7 @@
            openWindowInfo,
            skipLoad,
            triggeringRemoteType,
@@ -314,7 +325,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          }));
  
          if (focusUrlBar) {
-@@ -3146,6 +3252,12 @@
+@@ -3146,6 +3256,12 @@
          }
        }
  
@@ -327,7 +338,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        // Additionally send pinned tab events
        if (pinned) {
          this.#notifyPinnedStatus(t);
-@@ -3349,10 +3461,10 @@
+@@ -3349,10 +3465,10 @@
          isAdoptingGroup = false,
          isUserTriggered = false,
          telemetryUserCreateSource = "unknown",
@@ -339,7 +350,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        }
  
        if (!color) {
-@@ -3373,9 +3485,14 @@
+@@ -3373,9 +3489,14 @@
          label,
          isAdoptingGroup
        );
@@ -356,7 +367,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        );
        group.addTabs(tabs);
  
-@@ -3496,7 +3613,7 @@
+@@ -3496,7 +3617,7 @@
        }
  
        this.#handleTabMove(tab, () =>
@@ -365,7 +376,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        );
      }
  
-@@ -3698,6 +3815,7 @@
+@@ -3698,6 +3819,7 @@
          openWindowInfo,
          skipLoad,
          triggeringRemoteType,
@@ -373,7 +384,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        }
      ) {
        // If we don't have a preferred remote type (or it is `NOT_REMOTE`), and
-@@ -3767,6 +3885,7 @@
+@@ -3767,6 +3889,7 @@
            openWindowInfo,
            name,
            skipLoad,
@@ -381,7 +392,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          });
        }
  
-@@ -3955,7 +4074,7 @@
+@@ -3955,7 +4078,7 @@
          // Add a new tab if needed.
          if (!tab) {
            let createLazyBrowser =
@@ -390,7 +401,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
  
            let url = "about:blank";
            if (tabData.entries?.length) {
-@@ -3992,8 +4111,10 @@
+@@ -3992,8 +4115,10 @@
              insertTab: false,
              skipLoad: true,
              preferredRemoteType,
@@ -402,7 +413,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
            if (select) {
              tabToSelect = tab;
            }
-@@ -4005,7 +4126,8 @@
+@@ -4005,7 +4130,8 @@
            this.pinTab(tab);
            // Then ensure all the tab open/pinning information is sent.
            this._fireTabOpen(tab, {});
@@ -412,7 +423,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
            let { groupId } = tabData;
            const tabGroup = tabGroupWorkingData.get(groupId);
            // if a tab refers to a tab group we don't know, skip any group
-@@ -4019,7 +4141,10 @@
+@@ -4019,7 +4145,10 @@
                  tabGroup.stateData.id,
                  tabGroup.stateData.color,
                  tabGroup.stateData.collapsed,
@@ -424,7 +435,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
                );
                tabsFragment.appendChild(tabGroup.node);
              }
-@@ -4064,9 +4189,23 @@
+@@ -4064,9 +4193,23 @@
        // to remove the old selected tab.
        if (tabToSelect) {
          let leftoverTab = this.selectedTab;
@@ -440,15 +451,15 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
 +            gZenWorkspaces._initialTab._shouldRemove = true;
 +          }
 +        }
-+      }
+       }
 +      else {
 +        gZenWorkspaces._tabToRemoveForEmpty = this.selectedTab;
-       }
++      }
 +      this._hasAlreadyInitializedZenSessionStore = true;
  
        if (tabs.length > 1 || !tabs[0].selected) {
          this._updateTabsAfterInsert();
-@@ -4257,11 +4396,14 @@
+@@ -4257,11 +4400,14 @@
        if (ownerTab) {
          tab.owner = ownerTab;
        }
@@ -464,7 +475,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          if (
            !bulkOrderedOpen &&
            ((openerTab &&
-@@ -4273,7 +4415,7 @@
+@@ -4273,7 +4419,7 @@
            let lastRelatedTab =
              openerTab && this._lastRelatedTabMap.get(openerTab);
            let previousTab = lastRelatedTab || openerTab || this.selectedTab;
@@ -473,7 +484,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
              tabGroup = previousTab.group;
            }
            if (
-@@ -4284,7 +4426,7 @@
+@@ -4284,7 +4430,7 @@
            ) {
              elementIndex = Infinity;
            } else if (previousTab.visible) {
@@ -482,7 +493,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
            } else if (previousTab == FirefoxViewHandler.tab) {
              elementIndex = 0;
            }
-@@ -4312,14 +4454,14 @@
+@@ -4312,14 +4458,14 @@
        }
        // Ensure index is within bounds.
        if (tab.pinned) {
@@ -501,7 +512,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
  
        if (pinned && !itemAfter?.pinned) {
          itemAfter = null;
-@@ -4330,7 +4472,7 @@
+@@ -4330,7 +4476,7 @@
  
        this.tabContainer._invalidateCachedTabs();
  
@@ -510,7 +521,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          if (this.isTab(itemAfter) && itemAfter.group == tabGroup) {
            // Place at the front of, or between tabs in, the same tab group
            this.tabContainer.insertBefore(tab, itemAfter);
-@@ -4358,7 +4500,11 @@
+@@ -4358,7 +4504,11 @@
          const tabContainer = pinned
            ? this.tabContainer.pinnedTabsContainer
            : this.tabContainer;
@@ -522,7 +533,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        }
  
        this._updateTabsAfterInsert();
-@@ -4366,6 +4512,7 @@
+@@ -4366,6 +4516,7 @@
        if (pinned) {
          this._updateTabBarForPinnedTabs();
        }
@@ -530,7 +541,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
  
        TabBarVisibility.update();
      }
-@@ -4916,6 +5063,7 @@
+@@ -4916,6 +5067,7 @@
          telemetrySource,
        } = {}
      ) {
@@ -538,7 +549,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        // When 'closeWindowWithLastTab' pref is enabled, closing all tabs
        // can be considered equivalent to closing the window.
        if (
-@@ -5005,6 +5153,7 @@
+@@ -5005,6 +5157,7 @@
          if (lastToClose) {
            this.removeTab(lastToClose, aParams);
          }
@@ -546,7 +557,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        } catch (e) {
          console.error(e);
        }
-@@ -5043,6 +5192,12 @@
+@@ -5043,6 +5196,12 @@
          aTab._closeTimeNoAnimTimerId = Glean.browserTabclose.timeNoAnim.start();
        }
  
@@ -559,7 +570,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        // Handle requests for synchronously removing an already
        // asynchronously closing tab.
        if (!animate && aTab.closing) {
-@@ -5057,6 +5212,9 @@
+@@ -5057,6 +5216,9 @@
        // state).
        let tabWidth = window.windowUtils.getBoundsWithoutFlushing(aTab).width;
        let isLastTab = this.#isLastTabInWindow(aTab);
@@ -569,7 +580,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        if (
          !this._beginRemoveTab(aTab, {
            closeWindowFastpath: true,
-@@ -5105,7 +5263,13 @@
+@@ -5105,7 +5267,13 @@
          // We're not animating, so we can cancel the animation stopwatch.
          Glean.browserTabclose.timeAnim.cancel(aTab._closeTimeAnimTimerId);
          aTab._closeTimeAnimTimerId = null;
@@ -584,7 +595,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          return;
        }
  
-@@ -5239,7 +5403,7 @@
+@@ -5239,7 +5407,7 @@
            closeWindowWithLastTab != null
              ? closeWindowWithLastTab
              : !window.toolbar.visible ||
@@ -593,7 +604,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
  
          if (closeWindow) {
            // We've already called beforeunload on all the relevant tabs if we get here,
-@@ -5263,6 +5427,7 @@
+@@ -5263,6 +5431,7 @@
  
          newTab = true;
        }
@@ -601,7 +612,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        aTab._endRemoveArgs = [closeWindow, newTab];
  
        // swapBrowsersAndCloseOther will take care of closing the window without animation.
-@@ -5303,13 +5468,7 @@
+@@ -5303,13 +5472,7 @@
        aTab._mouseleave();
  
        if (newTab) {
@@ -616,7 +627,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        } else {
          TabBarVisibility.update();
        }
-@@ -5442,6 +5601,7 @@
+@@ -5442,6 +5605,7 @@
          this.tabs[i]._tPos = i;
        }
  
@@ -624,7 +635,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        if (!this._windowIsClosing) {
          // update tab close buttons state
          this.tabContainer._updateCloseButtons();
-@@ -5663,6 +5823,7 @@
+@@ -5663,6 +5827,7 @@
        }
  
        let excludeTabs = new Set(aExcludeTabs);
@@ -632,7 +643,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
  
        // If this tab has a successor, it should be selectable, since
        // hiding or closing a tab removes that tab as a successor.
-@@ -5675,13 +5836,13 @@
+@@ -5675,13 +5840,13 @@
          !excludeTabs.has(aTab.owner) &&
          Services.prefs.getBoolPref("browser.tabs.selectOwnerOnClose")
        ) {
@@ -648,7 +659,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        );
  
        let tab = this.tabContainer.findNextTab(aTab, {
-@@ -5697,7 +5858,7 @@
+@@ -5697,7 +5862,7 @@
        }
  
        if (tab) {
@@ -657,7 +668,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        }
  
        // If no qualifying visible tab was found, see if there is a tab in
-@@ -5718,7 +5879,7 @@
+@@ -5718,7 +5883,7 @@
          });
        }
  
@@ -666,7 +677,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
      }
  
      _blurTab(aTab) {
-@@ -5729,7 +5890,7 @@
+@@ -5729,7 +5894,7 @@
       * @returns {boolean}
       *   False if swapping isn't permitted, true otherwise.
       */
@@ -675,7 +686,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        // Do not allow transfering a private tab to a non-private window
        // and vice versa.
        if (
-@@ -5783,6 +5944,7 @@
+@@ -5783,6 +5948,7 @@
        // fire the beforeunload event in the process.  Close the other
        // window if this was its last tab.
        if (
@@ -683,7 +694,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          !remoteBrowser._beginRemoveTab(aOtherTab, {
            adoptedByTab: aOurTab,
            closeWindowWithLastTab: true,
-@@ -5794,7 +5956,7 @@
+@@ -5794,7 +5960,7 @@
        // If this is the last tab of the window, hide the window
        // immediately without animation before the docshell swap, to avoid
        // about:blank being painted.
@@ -692,7 +703,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        if (closeWindow) {
          let win = aOtherTab.ownerGlobal;
          win.windowUtils.suppressAnimation(true);
-@@ -5918,11 +6080,13 @@
+@@ -5918,11 +6084,13 @@
        }
  
        // Finish tearing down the tab that's going away.
@@ -706,7 +717,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
  
        this.setTabTitle(aOurTab);
  
-@@ -6124,10 +6288,10 @@
+@@ -6124,10 +6292,10 @@
        SessionStore.deleteCustomTabValue(aTab, "hiddenBy");
      }
  
@@ -719,7 +730,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          aTab.selected ||
          aTab.closing ||
          // Tabs that are sharing the screen, microphone or camera cannot be hidden.
-@@ -6185,7 +6349,8 @@
+@@ -6185,7 +6353,8 @@
       *
       * @param {MozTabbrowserTab|MozTabbrowserTabGroup|MozTabbrowserTabGroup.labelElement} aTab
       */
@@ -729,7 +740,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        if (this.tabs.length == 1) {
          return null;
        }
-@@ -6209,12 +6374,14 @@
+@@ -6209,12 +6378,14 @@
        }
  
        // tell a new window to take the "dropped" tab
@@ -745,7 +756,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
      }
  
      /**
-@@ -6319,7 +6486,7 @@
+@@ -6319,7 +6490,7 @@
       *   `true` if element is a `<tab-group>`
       */
      isTabGroup(element) {
@@ -754,7 +765,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
      }
  
      /**
-@@ -6404,8 +6571,8 @@
+@@ -6404,8 +6575,8 @@
        }
  
        // Don't allow mixing pinned and unpinned tabs.
@@ -765,7 +776,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        } else {
          tabIndex = Math.max(tabIndex, this.pinnedTabCount);
        }
-@@ -6431,10 +6598,16 @@
+@@ -6431,10 +6602,16 @@
        this.#handleTabMove(
          element,
          () => {
@@ -784,7 +795,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
            if (neighbor && this.isTab(element) && tabIndex > element._tPos) {
              neighbor.after(element);
            } else {
-@@ -6492,23 +6665,31 @@
+@@ -6492,23 +6669,31 @@
      #moveTabNextTo(element, targetElement, moveBefore = false, metricsContext) {
        if (this.isTabGroupLabel(targetElement)) {
          targetElement = targetElement.group;
@@ -822,7 +833,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        } else if (!element.pinned && targetElement && targetElement.pinned) {
          // If the caller asks to move an unpinned element next to a pinned
          // tab, move the unpinned element to be the first unpinned element
-@@ -6521,14 +6702,34 @@
+@@ -6521,14 +6706,34 @@
          //    move the tab group right before the first unpinned tab.
          // 4. Moving a tab group and the first unpinned tab is grouped:
          //    move the tab group right before the first unpinned tab's tab group.
@@ -858,7 +869,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          element.pinned
            ? this.tabContainer.pinnedTabsContainer
            : this.tabContainer;
-@@ -6537,7 +6738,7 @@
+@@ -6537,7 +6742,7 @@
          element,
          () => {
            if (moveBefore) {
@@ -867,7 +878,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
            } else if (targetElement) {
              targetElement.after(element);
            } else {
-@@ -6607,10 +6808,10 @@
+@@ -6607,10 +6812,10 @@
       * @param {TabMetricsContext} [metricsContext]
       */
      moveTabToGroup(aTab, aGroup, metricsContext) {
@@ -880,7 +891,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          return;
        }
        if (aTab.group && aTab.group.id === aGroup.id) {
-@@ -6656,6 +6857,7 @@
+@@ -6656,6 +6861,7 @@
  
        let state = {
          tabIndex: tab._tPos,
@@ -888,7 +899,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        };
        if (tab.visible) {
          state.elementIndex = tab.elementIndex;
-@@ -6682,7 +6884,7 @@
+@@ -6682,7 +6888,7 @@
        let changedTabGroup =
          previousTabState.tabGroupId != currentTabState.tabGroupId;
  
@@ -897,7 +908,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
          tab.dispatchEvent(
            new CustomEvent("TabMove", {
              bubbles: true,
-@@ -6723,6 +6925,10 @@
+@@ -6723,6 +6929,10 @@
  
        moveActionCallback();
  
@@ -908,7 +919,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        // Clear tabs cache after moving nodes because the order of tabs may have
        // changed.
        this.tabContainer._invalidateCachedTabs();
-@@ -6815,6 +7021,8 @@
+@@ -6815,6 +7025,8 @@
          params.userContextId = aTab.getAttribute("usercontextid");
        }
        let newTab = this.addWebTab("about:blank", params);
@@ -917,7 +928,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
        let newBrowser = this.getBrowserForTab(newTab);
  
        aTab.container.tabDragAndDrop.finishAnimateTabMove();
-@@ -7623,7 +7831,7 @@
+@@ -7623,7 +7835,7 @@
              // preventDefault(). It will still raise the window if appropriate.
              break;
            }
@@ -926,7 +937,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
            window.focus();
            aEvent.preventDefault();
            break;
-@@ -7640,7 +7848,6 @@
+@@ -7640,7 +7852,6 @@
          }
          case "TabGroupCollapse":
            aEvent.target.tabs.forEach(tab => {
@@ -934,7 +945,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
            });
            break;
          case "TabGroupCreateByUser":
-@@ -7800,7 +8007,9 @@
+@@ -7800,7 +8011,9 @@
  
          let filter = this._tabFilters.get(tab);
          if (filter) {
@@ -944,7 +955,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
  
            let listener = this._tabListeners.get(tab);
            if (listener) {
-@@ -8589,6 +8798,7 @@
+@@ -8589,6 +8802,7 @@
              aWebProgress.isTopLevel
            ) {
              this.mTab.setAttribute("busy", "true");
@@ -952,7 +963,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
              gBrowser._tabAttrModified(this.mTab, ["busy"]);
              this.mTab._notselectedsinceload = !this.mTab.selected;
            }
-@@ -8670,6 +8880,7 @@
+@@ -8670,6 +8884,7 @@
          // known defaults. Note we use the original URL since about:newtab
          // redirects to a prerendered page.
          const shouldRemoveFavicon =
@@ -960,7 +971,7 @@ index 42027bfa55eab8ea9298a7d425f2ded45188f7f3..0b22d01a9f75c08da43edc40100fa156
            !this.mBrowser.mIconURL &&
            !ignoreBlank &&
            !(originalLocation.spec in FAVICON_DEFAULTS);
-@@ -9623,7 +9834,7 @@ var TabContextMenu = {
+@@ -9623,7 +9838,7 @@ var TabContextMenu = {
      );
      contextUnpinSelectedTabs.hidden =
        !this.contextTab.pinned || !this.multiselected;
diff --git a/src/browser/modules/BrowserWindowTracker-sys-mjs.patch b/src/browser/modules/BrowserWindowTracker-sys-mjs.patch
new file mode 100644
index 000000000..ce68986dc
--- /dev/null
+++ b/src/browser/modules/BrowserWindowTracker-sys-mjs.patch
@@ -0,0 +1,25 @@
+diff --git a/browser/modules/BrowserWindowTracker.sys.mjs b/browser/modules/BrowserWindowTracker.sys.mjs
+index f2b64cfbdf579c67496b785c8efafc69bf20372a..f3d8755aa7d122d9ee5c449a02cceb629aa6aa00 100644
+--- a/browser/modules/BrowserWindowTracker.sys.mjs
++++ b/browser/modules/BrowserWindowTracker.sys.mjs
+@@ -325,6 +325,7 @@ export const BrowserWindowTracker = {
+     args = null,
+     remote = undefined,
+     fission = undefined,
++    zenSyncedWindow = true,
+   } = {}) {
+     let windowFeatures = "chrome,dialog=no";
+     if (all) {
+@@ -378,6 +379,12 @@ export const BrowserWindowTracker = {
+       windowFeatures,
+       args
+     );
++    win._zenStartupSyncFlag = Services.prefs.getBoolPref("zen.window-sync.prefer-unsynced-windows")
++      ? (zenSyncedWindow ? 'unsynced' : 'synced')
++      : (zenSyncedWindow ? 'synced' : 'unsynced');
++    if (win._zenStartupSyncFlag === 'unsynced' && openerWindow) {
++      win._zenStartupUnsyncedUserContextId = openerWindow.gZenWorkspaces.getCurrentSpaceContainerId();
++    }
+     this.registerOpeningWindow(win, isPrivate);
+ 
+     win.addEventListener(
diff --git a/src/zen/common/modules/ZenCommonUtils.mjs b/src/zen/common/modules/ZenCommonUtils.mjs
index 905939d8a..143ece00e 100644
--- a/src/zen/common/modules/ZenCommonUtils.mjs
+++ b/src/zen/common/modules/ZenCommonUtils.mjs
@@ -51,6 +51,17 @@ export class nsZenMultiWindowFeature {
       }
     }
   }
+
+  forEachWindowSync(callback) {
+    for (const browser of nsZenMultiWindowFeature.browsers) {
+      try {
+        if (browser.closed) continue;
+        callback(browser);
+      } catch (e) {
+        console.error(e);
+      }
+    }
+  }
 }
 
 export class nsZenDOMOperatedFeature {
diff --git a/src/zen/common/styles/zen-theme.css b/src/zen/common/styles/zen-theme.css
index dba4b97b4..2187501c3 100644
--- a/src/zen/common/styles/zen-theme.css
+++ b/src/zen/common/styles/zen-theme.css
@@ -235,14 +235,14 @@
     );
     --zen-main-browser-background-toolbar: var(--zen-main-browser-background);
     --zen-primary-color: light-dark(rgb(93, 42, 107), rgb(110, 48, 125)) !important;
-    --toolbox-textcolor: currentColor !important;
+    --toolbox-textcolor: color-mix(in srgb, currentColor 95%, transparent) !important;
   }
 
   &[zen-unsynced-window='true'] {
     --zen-main-browser-background: color-mix(in srgb, light-dark(rgb(196, 202, 229), rgb(8, 9, 40)) 60%, var(--zen-themed-toolbar-bg-transparent));
     --zen-main-browser-background-toolbar: var(--zen-main-browser-background);
     --zen-primary-color: light-dark(rgb(100, 115, 255), rgb(80, 90, 200)) !important;
-    --toolbox-textcolor: currentColor !important;
+    --toolbox-textcolor: color-mix(in srgb, currentColor 95%, transparent) !important;
     --zen-workspace-indicator-height: 42px;
   }
 
diff --git a/src/zen/common/zen-sets.js b/src/zen/common/zen-sets.js
index 25cfe4b01..437ad3a77 100644
--- a/src/zen/common/zen-sets.js
+++ b/src/zen/common/zen-sets.js
@@ -126,6 +126,9 @@ document.addEventListener(
           gZenWorkspaces.unloadWorkspace();
           break;
         }
+        case 'cmd_zenNewNavigatorUnsynced':
+          OpenBrowserWindow({ zenSyncedWindow: false });
+          break;
         default:
           gZenGlanceManager.handleMainCommandSet(event);
           if (event.target.id.startsWith('cmd_zenWorkspaceSwitch')) {
diff --git a/src/zen/kbs/ZenKeyboardShortcuts.mjs b/src/zen/kbs/ZenKeyboardShortcuts.mjs
index 1102400df..9badca34c 100644
--- a/src/zen/kbs/ZenKeyboardShortcuts.mjs
+++ b/src/zen/kbs/ZenKeyboardShortcuts.mjs
@@ -47,6 +47,7 @@ const KEYCODE_MAP = {
 const defaultKeyboardGroups = {
   windowAndTabManagement: [
     'zen-window-new-shortcut',
+    'zen-new-unsynced-window-shortcut',
     'zen-tab-new-shortcut',
     'zen-key-enter-full-screen',
     'zen-key-exit-full-screen',
@@ -71,7 +72,6 @@ const defaultKeyboardGroups = {
     'zen-nav-reload-shortcut-skip-cache',
     'zen-nav-reload-shortcut',
     'zen-key-stop',
-    'zen-window-new-shortcut',
     'zen-private-browsing-shortcut',
     'id:goHome',
     'id:key_gotoHistory',
@@ -804,7 +804,7 @@ class nsZenKeyboardShortcutsLoader {
 }
 
 class nsZenKeyboardShortcutsVersioner {
-  static LATEST_KBS_VERSION = 13;
+  static LATEST_KBS_VERSION = 14;
 
   constructor() {}
 
@@ -1087,6 +1087,8 @@ class nsZenKeyboardShortcutsVersioner {
     }
 
     if (version < 13) {
+      // Migrate from version 12 to 13
+      // Add shortcut to close all unpinned tabs: Default Accel+Shift+K
       data.push(
         new KeyShortcut(
           'zen-close-all-unpinned-tabs',
@@ -1100,6 +1102,22 @@ class nsZenKeyboardShortcutsVersioner {
       );
     }
 
+    if (version < 14) {
+      // Migrate from version 13 to 14
+      // Add shortcut to open a new unsynced window: Default accelt+option+N (Ctrl+Alt+N on non-macOS)
+      data.push(
+        new KeyShortcut(
+          'zen-new-unsynced-window',
+          'N',
+          '',
+          ZEN_OTHER_SHORTCUTS_GROUP,
+          nsKeyShortcutModifiers.fromObject({ accel: true, alt: true }),
+          'cmd_zenNewNavigatorUnsynced',
+          'zen-new-unsynced-window-shortcut'
+        )
+      );
+    }
+
     return data;
   }
 }
diff --git a/src/zen/sessionstore/ZenSessionManager.sys.mjs b/src/zen/sessionstore/ZenSessionManager.sys.mjs
index 435681c94..543b8e5af 100644
--- a/src/zen/sessionstore/ZenSessionManager.sys.mjs
+++ b/src/zen/sessionstore/ZenSessionManager.sys.mjs
@@ -200,13 +200,19 @@ export class nsZenSessionManager {
     // Restore all windows with the same sidebar object, this will
     // guarantee that all tabs, groups, folders and split view data
     // are properly synced across all windows.
+    const allowRestoreUnsynced = Services.prefs.getBoolPref(
+      'zen.session-store.restore-unsynced-windows',
+      true
+    );
     this.log(`Restoring Zen session data into ${initialState.windows?.length || 0} windows`);
     for (let i = 0; i < initialState.windows.length; i++) {
       let winData = initialState.windows[i];
       if (winData.isZenUnsynced) {
-        // We don't wan't to restore any unsynced windows with the sidebar data.
-        this.log('Skipping restore of unsynced window');
-        delete initialState.windows[i];
+        if (!allowRestoreUnsynced) {
+          // We don't wan't to restore any unsynced windows with the sidebar data.
+          this.log('Skipping restore of unsynced window');
+          delete initialState.windows[i];
+        }
         continue;
       }
       this.#restoreWindowData(winData);
diff --git a/src/zen/workspaces/ZenGradientGenerator.mjs b/src/zen/workspaces/ZenGradientGenerator.mjs
index 09f8aafba..2246ce4ef 100644
--- a/src/zen/workspaces/ZenGradientGenerator.mjs
+++ b/src/zen/workspaces/ZenGradientGenerator.mjs
@@ -593,7 +593,7 @@ export class nsZenThemePicker extends nsZenMultiWindowFeature {
     this.panel.querySelector('#PanelUI-zen-gradient-generator-custom-list').prepend(dot);
     this.customColorInput.value = '';
     document.getElementById('PanelUI-zen-gradient-generator-custom-opacity').value = 1;
-    await this.updateCurrentWorkspace();
+    this.updateCurrentWorkspace();
   }
 
   handlePanelCommand(event) {
@@ -1313,17 +1313,17 @@ export class nsZenThemePicker extends nsZenMultiWindowFeature {
     return isDarkMode ? [255, 255, 255, 0.6] : [0, 0, 0, 0.6]; // Default toolbar
   }
 
-  async onWorkspaceChange(workspace, skipUpdate = false, theme = null) {
+  onWorkspaceChange(workspace, skipUpdate = false, theme = null) {
     const uuid = workspace.uuid;
     // Use theme from workspace object or passed theme
     let workspaceTheme = theme || workspace.theme;
 
-    await this.forEachWindow(async (browser) => {
+    this.forEachWindowSync((browser) => {
       if (!browser.gZenThemePicker?.promiseInitialized) {
         return;
       }
 
-      if (browser.closing || (await browser.gZenThemePicker?.promiseInitialized)) {
+      if (browser.closing) {
         return;
       }
 
@@ -1602,7 +1602,7 @@ export class nsZenThemePicker extends nsZenMultiWindowFeature {
     }
   }
 
-  async updateCurrentWorkspace(skipSave = true) {
+  updateCurrentWorkspace(skipSave = true) {
     this.updated = skipSave;
     const dots = this.panel.querySelectorAll('.zen-theme-picker-dot');
     const colors = Array.from(dots)
@@ -1637,12 +1637,12 @@ export class nsZenThemePicker extends nsZenMultiWindowFeature {
       gZenWorkspaces.saveWorkspace(currentWorkspace);
     }
 
-    await this.onWorkspaceChange(currentWorkspace, skipSave, skipSave ? gradient : null);
+    this.onWorkspaceChange(currentWorkspace, skipSave, skipSave ? gradient : null);
   }
 
-  async handlePanelClose() {
+  handlePanelClose() {
     if (this.updated) {
-      await this.updateCurrentWorkspace(false);
+      this.updateCurrentWorkspace(false);
     }
     this.uninitThemePicker();
   }
diff --git a/src/zen/workspaces/ZenWorkspace.mjs b/src/zen/workspaces/ZenWorkspace.mjs
index b09f98480..88f629562 100644
--- a/src/zen/workspaces/ZenWorkspace.mjs
+++ b/src/zen/workspaces/ZenWorkspace.mjs
@@ -256,14 +256,6 @@ export class nsZenWorkspace extends MozXULElement {
         tabPinCallback();
       }
     });
-
-    this.dispatchEvent(
-      new CustomEvent('ZenWorkspaceAttached', {
-        bubbles: true,
-        composed: true,
-        detail: { workspace: this },
-      })
-    );
   }
 
   disconnectedCallback() {
diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index d2853312d..9f7b53435 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -306,7 +306,7 @@ class nsZenWorkspaces {
   }
 
   registerPinnedResizeObserver() {
-    if (!this._hasInitializedTabsStrip) {
+    if (!this._hasInitializedTabsStrip || !this._pinnedTabsResizeObserver) {
       return;
     }
     this._pinnedTabsResizeObserver.disconnect();
@@ -369,15 +369,13 @@ class nsZenWorkspaces {
     return document.getElementById(workspaceId);
   }
 
-  async #initializeTabsStripSections() {
-    await SessionStore.promiseInitialized;
-    await SessionStore.promiseAllWindowsRestored;
+  #initializeTabsStripSections() {
     const perifery = document.getElementById('tabbrowser-arrowscrollbox-periphery');
     perifery.setAttribute('hidden', 'true');
     const tabs = gBrowser.tabContainer.allTabs;
     const workspaces = this.getWorkspaces();
     for (const workspace of workspaces) {
-      await this.#createWorkspaceTabsSection(workspace, tabs);
+      this.#createWorkspaceTabsSection(workspace, tabs);
     }
     if (tabs.length) {
       const defaultSelectedContainer = this.workspaceElement(this.activeWorkspace)?.querySelector(
@@ -438,12 +436,16 @@ class nsZenWorkspaces {
     return essentialsContainer;
   }
 
-  getCurrentEssentialsContainer() {
+  getCurrentSpaceContainerId() {
     const currentWorkspace = this.getActiveWorkspaceFromCache();
-    return this.getEssentialsSection(currentWorkspace?.containerTabId);
+    return currentWorkspace?.containerTabId || 0;
   }
 
-  async #createWorkspaceTabsSection(workspace, tabs = []) {
+  getCurrentEssentialsContainer() {
+    return this.getEssentialsSection(this.getCurrentSpaceContainerId());
+  }
+
+  #createWorkspaceTabsSection(workspace, tabs = []) {
     const workspaceWrapper = document.createXULElement('zen-workspace');
     const container = document.getElementById('tabbrowser-arrowscrollbox');
     workspaceWrapper.id = workspace.uuid;
@@ -454,24 +456,14 @@ class nsZenWorkspaces {
     if (document.documentElement.hasAttribute('zen-creating-workspace')) {
       workspaceWrapper.hidden = true; // Hide workspace while creating it
     }
-
-    await new Promise((resolve) => {
-      workspaceWrapper.addEventListener(
-        'ZenWorkspaceAttached',
-        () => {
-          this.#organizeTabsToWorkspaceSections(
-            workspace,
-            workspaceWrapper.tabsContainer,
-            workspaceWrapper.pinnedTabsContainer,
-            tabs
-          );
-          workspaceWrapper.checkPinsExistence();
-          resolve();
-        },
-        { once: true }
-      );
-      container.appendChild(workspaceWrapper);
-    });
+    container.appendChild(workspaceWrapper);
+    this.#organizeTabsToWorkspaceSections(
+      workspace,
+      workspaceWrapper.tabsContainer,
+      workspaceWrapper.pinnedTabsContainer,
+      tabs
+    );
+    workspaceWrapper.checkPinsExistence();
   }
 
   #organizeTabsToWorkspaceSections(workspace, section, pinnedSection, tabs) {
@@ -864,16 +856,16 @@ class nsZenWorkspaces {
     return this._workspaceCache;
   }
 
-  async restoreWorkspacesFromSessionStore(aWinData = {}) {
+  restoreWorkspacesFromSessionStore(aWinData = {}) {
     if (this.#hasInitialized || !this.workspaceEnabled) {
       return;
     }
     const spacesFromStore = aWinData.spaces || [];
     this._workspaceCache = spacesFromStore.length
       ? [...spacesFromStore]
-      : [await this.createAndSaveWorkspace('Space', undefined, true)];
+      : [this.#createWorkspaceData('Space', undefined, true)];
     this.activeWorkspace = aWinData.activeZenSpace || this._workspaceCache[0].uuid;
-    await this.initializeWorkspaces();
+    let promise = this.#initializeWorkspaces();
     for (const workspace of spacesFromStore) {
       const element = this.workspaceElement(workspace.uuid);
       if (element) {
@@ -885,42 +877,44 @@ class nsZenWorkspaces {
       delete workspace.hasCollapsedPinnedTabs;
     }
     this.#hasInitialized = true;
+    return promise;
   }
 
-  async initializeWorkspaces() {
+  #initializeWorkspaces() {
     let activeWorkspace = this.getActiveWorkspace();
     this.activeWorkspace = activeWorkspace?.uuid;
-    await gZenSessionStore.promiseInitialized;
     try {
       if (activeWorkspace) {
         window.gZenThemePicker = new nsZenThemePicker();
-        await gZenThemePicker.onWorkspaceChange(activeWorkspace);
+        gZenThemePicker.onWorkspaceChange(activeWorkspace);
       }
     } catch (e) {
       console.error('gZenWorkspaces: Error initializing theme picker', e);
     }
-    await this.#initializeTabsStripSections();
+    this.#initializeTabsStripSections();
     this.#initializeEmptyTab();
-    await this.workspaceBookmarks();
-    await this.changeWorkspace(activeWorkspace, { onInit: true });
-    this.#fixTabPositions();
-    this.onWindowResize();
-    this._resolveInitialized();
-    this.#clearAnyZombieTabs(); // Dont call with await
-    delete this._resolveInitialized;
+    return (async () => {
+      await this.workspaceBookmarks();
+      await this.changeWorkspace(activeWorkspace, { onInit: true });
+      this.#fixTabPositions();
+      this.onWindowResize();
+      this._resolveInitialized();
+      this.#clearAnyZombieTabs(); // Dont call with await
+      delete this._resolveInitialized;
 
-    const tabUpdateListener = this.updateTabsContainers.bind(this);
-    window.addEventListener('TabOpen', tabUpdateListener);
-    window.addEventListener('TabClose', tabUpdateListener);
-    window.addEventListener('TabAddedToEssentials', tabUpdateListener);
-    window.addEventListener('TabRemovedFromEssentials', tabUpdateListener);
-    window.addEventListener('TabPinned', tabUpdateListener);
-    window.addEventListener('TabUnpinned', tabUpdateListener);
-    window.addEventListener('aftercustomization', tabUpdateListener);
-    window.addEventListener('TabSelect', this.onLocationChange.bind(this));
-    window.addEventListener('TabBrowserInserted', this.onTabBrowserInserted.bind(this));
+      const tabUpdateListener = this.updateTabsContainers.bind(this);
+      window.addEventListener('TabOpen', tabUpdateListener);
+      window.addEventListener('TabClose', tabUpdateListener);
+      window.addEventListener('TabAddedToEssentials', tabUpdateListener);
+      window.addEventListener('TabRemovedFromEssentials', tabUpdateListener);
+      window.addEventListener('TabPinned', tabUpdateListener);
+      window.addEventListener('TabUnpinned', tabUpdateListener);
+      window.addEventListener('aftercustomization', tabUpdateListener);
+      window.addEventListener('TabSelect', this.onLocationChange.bind(this));
+      window.addEventListener('TabBrowserInserted', this.onTabBrowserInserted.bind(this));
 
-    this.updateWorkspacesChangeContextMenu();
+      this.updateWorkspacesChangeContextMenu();
+    })();
   }
 
   async selectStartPage() {
@@ -1356,9 +1350,7 @@ class nsZenWorkspaces {
     // Add any new workspace elements here
     for (const workspace of aWorkspaces) {
       if (!this.workspaceElement(workspace.uuid)) {
-        this.#createWorkspaceTabsSection(workspace).catch((e) => {
-          console.error('Error creating workspace tabs section:', e);
-        });
+        this.#createWorkspaceTabsSection(workspace);
         hasChanged = true;
       }
     }
@@ -2386,7 +2378,7 @@ class nsZenWorkspaces {
     }
   }
 
-  async _createWorkspaceData(name, icon, tabs, moveTabs = true, containerTabId = 0) {
+  #createWorkspaceData(name, icon, containerTabId = 0) {
     let workspace = {
       uuid: gZenUIManager.generateUuidv4(),
       icon: icon,
@@ -2394,11 +2386,6 @@ class nsZenWorkspaces {
       theme: nsZenThemePicker.getTheme([]),
       containerTabId,
     };
-    if (moveTabs) {
-      this.#prepareNewWorkspace(workspace);
-      await this.#createWorkspaceTabsSection(workspace, tabs);
-      await this._organizeWorkspaceStripLocations(workspace);
-    }
     return workspace;
   }
 
@@ -2425,13 +2412,12 @@ class nsZenWorkspaces {
         !child.hasAttribute('zen-empty-tab') &&
         !child.hasAttribute('zen-essential')
     );
-    let workspaceData = await this._createWorkspaceData(
-      name,
-      icon,
-      extraTabs,
-      !dontChange,
-      containerTabId
-    );
+    let workspaceData = this.#createWorkspaceData(name, icon, containerTabId);
+    if (!dontChange) {
+      this.#prepareNewWorkspace(workspaceData);
+      this.#createWorkspaceTabsSection(workspaceData, extraTabs);
+      await this._organizeWorkspaceStripLocations(workspaceData);
+    }
     if (!this.currentWindowIsSyncing) {
       this._tempWorkspace = workspaceData;
     } else {
diff --git a/src/zen/workspaces/zen-workspaces.css b/src/zen/workspaces/zen-workspaces.css
index 276cda68e..19b0cbeef 100644
--- a/src/zen/workspaces/zen-workspaces.css
+++ b/src/zen/workspaces/zen-workspaces.css
@@ -75,7 +75,7 @@
 
     &:hover,
     &[dragged='true']{
-      background-color: var(--toolbarbutton-hover-background);
+      background-color: var(--zen-toolbar-element-bg);
     }
 
     & label {
@@ -239,7 +239,7 @@
 
     :root[zen-unsynced-window] & {
       pointer-events: none;
-      background: color-mix(in srgb, currentColor 20%, transparent);
+      background: var(--zen-toolbar-element-bg);
       padding: 4px 8px;
       border-radius: 99px;
       font-size: 10px;