diff --git a/locales/en-US/browser/browser/preferences/zen-preferences.ftl b/locales/en-US/browser/browser/preferences/zen-preferences.ftl
index ea49e2517..d053124e2 100644
--- a/locales/en-US/browser/browser/preferences/zen-preferences.ftl
+++ b/locales/en-US/browser/browser/preferences/zen-preferences.ftl
@@ -56,6 +56,9 @@ pane-settings-workspaces-title = Workspaces
 zen-tabs-unloader-enabled =
     .label = Enable Tab Unloader
 
+zen-tabs-close-on-back-with-no-history =
+    .label = Close tab and switch to its owner tab (or most recently used tab) when going back with no history
+
 zen-look-and-feel-compact-toolbar-themed =
     .label = Use themed background for compact toolbar
 
diff --git a/prefs/zen/zen.yaml b/prefs/zen/zen.yaml
index 469622931..c44a0e626 100644
--- a/prefs/zen/zen.yaml
+++ b/prefs/zen/zen.yaml
@@ -34,3 +34,6 @@
 
 - name: zen.tabs.open-pinned-in-new-tab
   value: true
+
+- name: zen.tabs.close-on-back-with-no-history
+  value: true
diff --git a/src/browser/base/content/browser-commands-js.patch b/src/browser/base/content/browser-commands-js.patch
index a475e0749..3c0aabfee 100644
--- a/src/browser/base/content/browser-commands-js.patch
+++ b/src/browser/base/content/browser-commands-js.patch
@@ -1,8 +1,19 @@
 diff --git a/browser/base/content/browser-commands.js b/browser/base/content/browser-commands.js
-index 939ca497b882b3f4200141ba1b6764fb5c846f45..36c830a503b004c0a332340f686c86cad68e9381 100644
+index 939ca497b882b3f4200141ba1b6764fb5c846f45..779cba5ff3df856a246321a36caa3725c054a314 100644
 --- a/browser/base/content/browser-commands.js
 +++ b/browser/base/content/browser-commands.js
-@@ -315,6 +315,10 @@ var BrowserCommands = {
+@@ -14,6 +14,10 @@ var BrowserCommands = {
+     const where = BrowserUtils.whereToOpenLink(aEvent, false, true);
+ 
+     if (where == "current") {
++      if (!gBrowser.webNavigation.canGoBack && gZenCommonActions.shouldCloseTabOnBack()) {
++        gBrowser.removeTab(gBrowser.selectedTab);
++        return;
++      }
+       try {
+         gBrowser.goBack();
+       } catch (ex) {}
+@@ -315,6 +319,10 @@ var BrowserCommands = {
        }
      }
  
@@ -13,7 +24,7 @@ index 939ca497b882b3f4200141ba1b6764fb5c846f45..36c830a503b004c0a332340f686c86ca
      // A notification intended to be useful for modular peformance tracking
      // starting as close as is reasonably possible to the time when the user
      // expressed the intent to open a new tab.  Since there are a lot of
-@@ -399,6 +403,11 @@ var BrowserCommands = {
+@@ -399,6 +407,11 @@ var BrowserCommands = {
        return;
      }
  
@@ -25,7 +36,7 @@ index 939ca497b882b3f4200141ba1b6764fb5c846f45..36c830a503b004c0a332340f686c86ca
      // Keyboard shortcuts that would close a tab that is pinned select the first
      // unpinned tab instead.
      if (
-@@ -406,8 +415,8 @@ var BrowserCommands = {
+@@ -406,8 +419,8 @@ var BrowserCommands = {
        (event.ctrlKey || event.metaKey || event.altKey) &&
        gBrowser.selectedTab.pinned
      ) {
diff --git a/src/browser/base/content/browser-gestureSupport-js.patch b/src/browser/base/content/browser-gestureSupport-js.patch
new file mode 100644
index 000000000..ef205d5df
--- /dev/null
+++ b/src/browser/base/content/browser-gestureSupport-js.patch
@@ -0,0 +1,13 @@
+diff --git a/browser/base/content/browser-gestureSupport.js b/browser/base/content/browser-gestureSupport.js
+index a28d54bf72c0e6495b9586f220d1859aac794936..66154668b9f85ffbaacea1e8351370659260227b 100644
+--- a/browser/base/content/browser-gestureSupport.js
++++ b/browser/base/content/browser-gestureSupport.js
+@@ -832,7 +832,7 @@ var gHistorySwipeAnimation = {
+    * @return true if there is a previous page in history, false otherwise.
+    */
+   canGoBack: function HSA_canGoBack() {
+-    return gBrowser.webNavigation.canGoBack;
++    return gBrowser.webNavigation.canGoBack || gZenCommonActions.shouldCloseTabOnBack();
+   },
+ 
+   /**
diff --git a/src/browser/base/content/browser-js.patch b/src/browser/base/content/browser-js.patch
index 8d2658275..4165d22e5 100644
--- a/src/browser/base/content/browser-js.patch
+++ b/src/browser/base/content/browser-js.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/base/content/browser.js b/browser/base/content/browser.js
-index b4b79e7fb3228ba91bd8afa08659be0d88883725..9e1d59b6a736107e55bda73686a4a627e4c0ba7c 100644
+index b4b79e7fb3228ba91bd8afa08659be0d88883725..b4801e2a3076139622d58f81943e61cd61ee1828 100644
 --- a/browser/base/content/browser.js
 +++ b/browser/base/content/browser.js
 @@ -31,6 +31,7 @@ ChromeUtils.defineESModuleGetters(this, {
@@ -10,7 +10,21 @@ index b4b79e7fb3228ba91bd8afa08659be0d88883725..9e1d59b6a736107e55bda73686a4a627
    DevToolsSocketStatus:
      "resource://devtools/shared/security/DevToolsSocketStatus.sys.mjs",
    DownloadUtils: "resource://gre/modules/DownloadUtils.sys.mjs",
-@@ -2298,6 +2299,8 @@ var XULBrowserWindow = {
+@@ -822,7 +823,12 @@ function UpdateBackForwardCommands(aWebNavigation) {
+ 
+   var backDisabled = backCommand.hasAttribute("disabled");
+   var forwardDisabled = forwardCommand.hasAttribute("disabled");
+-  if (backDisabled == aWebNavigation.canGoBack) {
++  var canGoBack = aWebNavigation.canGoBack;
++  if (!canGoBack) {
++    canGoBack = gZenCommonActions.shouldCloseTabOnBack();
++  }
++  
++  if (backDisabled == canGoBack) {
+     if (backDisabled) {
+       backCommand.removeAttribute("disabled");
+     } else {
+@@ -2298,6 +2304,8 @@ var XULBrowserWindow = {
      AboutReaderParent.updateReaderButton(gBrowser.selectedBrowser);
      TranslationsParent.onLocationChange(gBrowser.selectedBrowser);
  
@@ -19,7 +33,7 @@ index b4b79e7fb3228ba91bd8afa08659be0d88883725..9e1d59b6a736107e55bda73686a4a627
      PictureInPicture.updateUrlbarToggle(gBrowser.selectedBrowser);
  
      if (!gMultiProcessBrowser) {
-@@ -3809,7 +3812,7 @@ function warnAboutClosingWindow() {
+@@ -3809,7 +3817,7 @@ function warnAboutClosingWindow() {
  
    if (!isPBWindow && !toolbar.visible) {
      return gBrowser.warnAboutClosingTabs(
@@ -28,7 +42,7 @@ index b4b79e7fb3228ba91bd8afa08659be0d88883725..9e1d59b6a736107e55bda73686a4a627
        gBrowser.closingTabsEnum.ALL
      );
    }
-@@ -3849,7 +3852,7 @@ function warnAboutClosingWindow() {
+@@ -3849,7 +3857,7 @@ function warnAboutClosingWindow() {
      return (
        isPBWindow ||
        gBrowser.warnAboutClosingTabs(
@@ -37,7 +51,7 @@ index b4b79e7fb3228ba91bd8afa08659be0d88883725..9e1d59b6a736107e55bda73686a4a627
          gBrowser.closingTabsEnum.ALL
        )
      );
-@@ -3874,7 +3877,7 @@ function warnAboutClosingWindow() {
+@@ -3874,7 +3882,7 @@ function warnAboutClosingWindow() {
      AppConstants.platform != "macosx" ||
      isPBWindow ||
      gBrowser.warnAboutClosingTabs(
@@ -46,7 +60,7 @@ index b4b79e7fb3228ba91bd8afa08659be0d88883725..9e1d59b6a736107e55bda73686a4a627
        gBrowser.closingTabsEnum.ALL
      )
    );
-@@ -4796,6 +4799,9 @@ var ConfirmationHint = {
+@@ -4796,6 +4804,9 @@ var ConfirmationHint = {
      MozXULElement.insertFTLIfNeeded("toolkit/branding/brandings.ftl");
      MozXULElement.insertFTLIfNeeded("browser/confirmationHints.ftl");
      document.l10n.setAttributes(this._message, messageId, options.l10nArgs);
diff --git a/src/browser/components/preferences/zenTabsManagement.inc.xhtml b/src/browser/components/preferences/zenTabsManagement.inc.xhtml
index b8693566f..2943b863b 100644
--- a/src/browser/components/preferences/zenTabsManagement.inc.xhtml
+++ b/src/browser/components/preferences/zenTabsManagement.inc.xhtml
@@ -26,6 +26,9 @@
       <checkbox id="zenWorkspacesForceContainerTabsToWorkspace"
             data-l10n-id="zen-settings-workspaces-force-container-tabs-to-workspace"
             preference="zen.workspaces.force-container-workspace"/>
+      <checkbox id="zenTabsCloseOnBackWithNoHistory"
+            data-l10n-id="zen-tabs-close-on-back-with-no-history"
+            preference="zen.tabs.close-on-back-with-no-history"/>
 </groupbox>
 
 <hbox id="zenTabsUnloadCategory"
diff --git a/src/devtools/client/locales/en-US/toolbox-properties.patch b/src/devtools/client/locales/en-US/toolbox-properties.patch
new file mode 100644
index 000000000..3a8ae85fe
--- /dev/null
+++ b/src/devtools/client/locales/en-US/toolbox-properties.patch
@@ -0,0 +1,18 @@
+diff --git a/devtools/client/locales/en-US/toolbox.properties b/devtools/client/locales/en-US/toolbox.properties
+index d4f986b024d3505b8c151f8e0166a20ff1862c5d..b2fb69e8897abdacb090d5a6faca203656e7cd44 100644
+--- a/devtools/client/locales/en-US/toolbox.properties
++++ b/devtools/client/locales/en-US/toolbox.properties
+@@ -66,11 +66,11 @@ toolbox.androidElementPicker.mac.tooltip=Pick an element from the Android phone
+ 
+ # LOCALIZATION NOTE (toolbox.elementPicker.key)
+ # Key shortcut used to toggle the element picker.
+-toolbox.elementPicker.key=CmdOrCtrl+Shift+C
++toolbox.elementPicker.key=CmdOrCtrl+Shift+L
+ 
+ # LOCALIZATION NOTE (toolbox.elementPicker.mac.key)
+ # Key shortcut used to toggle the element picker for macOS.
+-toolbox.elementPicker.mac.key=Cmd+Opt+C
++toolbox.elementPicker.mac.key=Cmd+Opt+L
+ 
+ # LOCALIZATION NOTE (toolbox.viewCssSourceInStyleEditor.label)
+ # Used as a message in either tooltips or contextual menu items to open the
diff --git a/src/zen/common/ZenCommonUtils.mjs b/src/zen/common/ZenCommonUtils.mjs
index 4f2058fc9..f6b7cdc03 100644
--- a/src/zen/common/ZenCommonUtils.mjs
+++ b/src/zen/common/ZenCommonUtils.mjs
@@ -107,4 +107,19 @@ var gZenCommonActions = {
       timer = setTimeout(() => f.apply(this, args), delay);
     };
   },
+
+  /**
+   * Determines if a tab should be closed when navigating back with no history.
+   * Only tabs with an owner that are not pinned and not empty are eligible.
+   * Respects the user preference zen.tabs.close-on-back-with-no-history.
+   *
+   * @return {boolean} True if the tab should be closed on back
+   */
+  shouldCloseTabOnBack() {
+    if (!Services.prefs.getBoolPref('zen.tabs.close-on-back-with-no-history', true)) {
+      return false;
+    }
+    const tab = gBrowser.selectedTab;
+    return Boolean(tab.owner && !tab.pinned && !tab.hasAttribute('zen-empty-tab'));
+  },
 };
diff --git a/src/zen/tabs/ZenPinnedTabManager.mjs b/src/zen/tabs/ZenPinnedTabManager.mjs
index eebfadf06..779f3566b 100644
--- a/src/zen/tabs/ZenPinnedTabManager.mjs
+++ b/src/zen/tabs/ZenPinnedTabManager.mjs
@@ -778,10 +778,6 @@
         return;
       }
       const existingPin = this._pinsCache.find((p) => p.uuid === pin.uuid);
-      if (existingPin && existingPin === pin) {
-        // We want to avoid unnecessary writes
-        return;
-      }
       if (existingPin) {
         Object.assign(existingPin, pin);
       } else {
diff --git a/src/zen/tabs/ZenPinnedTabsStorage.mjs b/src/zen/tabs/ZenPinnedTabsStorage.mjs
index 425dbf2d1..bc11213f7 100644
--- a/src/zen/tabs/ZenPinnedTabsStorage.mjs
+++ b/src/zen/tabs/ZenPinnedTabsStorage.mjs
@@ -2,6 +2,8 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 var ZenPinnedTabsStorage = {
+  _saveCache: [],
+
   async init() {
     await this._ensureTable();
   },
@@ -74,6 +76,22 @@ var ZenPinnedTabsStorage = {
   },
 
   async savePin(pin, notifyObservers = true) {
+    // If we find the exact same pin in the cache, skip saving
+    const existingIndex = this._saveCache.findIndex((cachedPin) => cachedPin.uuid === pin.uuid);
+    if (existingIndex !== -1) {
+      const existingPin = this._saveCache[existingIndex];
+      const isSame = Object.keys(pin).every((key) => pin[key] === existingPin[key]);
+      if (isSame) {
+        return; // No changes, skip saving
+      } else {
+        // Update the cached pin
+        this._saveCache[existingIndex] = pin;
+      }
+    } else {
+      // Add to cache
+      this._saveCache.push(pin);
+    }
+
     const changedUUIDs = new Set();
 
     await PlacesUtils.withConnectionWrapper('ZenPinnedTabsStorage.savePin', async (db) => {
@@ -389,6 +407,11 @@ var ZenPinnedTabsStorage = {
   },
 
   async removePin(uuid, notifyObservers = true) {
+    const cachedIndex = this._saveCache.findIndex((cachedPin) => cachedPin.uuid === uuid);
+    if (cachedIndex !== -1) {
+      this._saveCache.splice(cachedIndex, 1);
+    }
+
     const changedUUIDs = [uuid];
 
     await PlacesUtils.withConnectionWrapper('ZenPinnedTabsStorage.removePin', async (db) => {