diff --git a/browser/base/content/browser-addons.js b/browser/base/content/browser-addons.js
index fadcbfca95ee28140579430c0371baad0e2f216a..1947b4ab1c0b4ba0099147c9f13ae78d6e425bdf 100644
--- a/browser/base/content/browser-addons.js
+++ b/browser/base/content/browser-addons.js
@@ -1069,7 +1069,7 @@ var gXPInstallObserver = {
       persistent: true,
       hideClose: true,
       popupOptions: {
-        position: "bottomright topright",
+        position: gZenUIManager.panelUIPosition(),
       },
     };
 
@@ -1279,7 +1279,7 @@ var gXPInstallObserver = {
       hideClose: true,
       timeout: Date.now() + 30000,
       popupOptions: {
-        position: "bottomright topright",
+        position: gZenUIManager.panelUIPosition(),
       },
     };
 
@@ -2211,7 +2211,7 @@ var gUnifiedExtensions = {
   // If the new ID is not added in NOTIFICATION_IDS, consider handling the case
   // in the "PopupNotificationsBeforeAnchor" handler elsewhere in this file.
   getPopupAnchorID(aBrowser, aWindow) {
-    const anchorID = "unified-extensions-button";
+    const anchorID = "zen-site-data-icon-button";
     const attr = anchorID + "popupnotificationanchor";
 
     if (!aBrowser[attr]) {
@@ -2222,7 +2222,7 @@ var gUnifiedExtensions = {
         anchorID
         // Anchor on the toolbar icon to position the popup right below the
         // button.
-      ).firstElementChild;
+      );
     }
 
     return anchorID;
@@ -2547,7 +2547,7 @@ var gUnifiedExtensions = {
     requestAnimationFrame(() => this.updateAttention());
   },
 
-  onToolbarVisibilityChange(toolbarId, isVisible) {
+  onToolbarVisibilityChange(toolbarId, isVisible, panel = this.panel) {
     // A list of extension widget IDs (possibly empty).
     let widgetIDs;
 
@@ -2561,7 +2561,7 @@ var gUnifiedExtensions = {
     }
 
     // The list of overflowed extensions in the extensions panel.
-    const overflowedExtensionsList = this.panel.querySelector(
+    const overflowedExtensionsList = panel.querySelector(
       "#overflowed-extensions-list"
     );
 
@@ -2662,37 +2662,41 @@ var gUnifiedExtensions = {
       );
       template.replaceWith(template.content);
       this._panel = document.getElementById("unified-extensions-panel");
-      let customizationArea = this._panel.querySelector(
-        "#unified-extensions-area"
-      );
-      CustomizableUI.registerPanelNode(
-        customizationArea,
-        CustomizableUI.AREA_ADDONS
-      );
-      CustomizableUI.addPanelCloseListeners(this._panel);
-
-      this._panel
-        .querySelector("#unified-extensions-manage-extensions")
-        .addEventListener("command", () => {
-          BrowserAddonUI.openAddonsMgr("addons://list/extension");
-        });
-
-      // Lazy-load the l10n strings. Those strings are used for the CUI and
-      // non-CUI extensions in the unified extensions panel.
-      document
-        .getElementById("unified-extensions-context-menu")
-        .querySelectorAll("[data-lazy-l10n-id]")
-        .forEach(el => {
-          el.setAttribute("data-l10n-id", el.getAttribute("data-lazy-l10n-id"));
-          el.removeAttribute("data-lazy-l10n-id");
-        });
+      this.initializePanel(this._panel);
     }
     return this._panel;
   },
 
+  initializePanel(panel) {
+    let customizationArea = panel.querySelector(
+      "#unified-extensions-area"
+    );
+    CustomizableUI.registerPanelNode(
+      customizationArea,
+      CustomizableUI.AREA_ADDONS
+    );
+    CustomizableUI.addPanelCloseListeners(panel);
+
+    panel
+      .querySelector("#unified-extensions-manage-extensions")
+      .addEventListener("command", () => {
+        BrowserAddonUI.openAddonsMgr("addons://list/extension");
+      });
+
+    // Lazy-load the l10n strings. Those strings are used for the CUI and
+    // non-CUI extensions in the unified extensions panel.
+    document
+      .getElementById("unified-extensions-context-menu")
+      .querySelectorAll("[data-lazy-l10n-id]")
+      .forEach(el => {
+        el.setAttribute("data-l10n-id", el.getAttribute("data-lazy-l10n-id"));
+        el.removeAttribute("data-lazy-l10n-id");
+      });
+  },
+
   // `aEvent` and `reason` are optional. If `reason` is specified, it should be
   // a valid argument to gUnifiedExtensions.recordButtonTelemetry().
-  async togglePanel(aEvent, reason) {
+  async togglePanel(aEvent, reason, panel = this._panel, view = "unified-extensions-view", button = this._button) {
     if (!CustomizationHandler.isCustomizing()) {
       if (aEvent) {
         if (
@@ -2714,6 +2718,7 @@ var gUnifiedExtensions = {
         // and no alternative content is available for display in the panel.
         const policies = this.getActivePolicies();
         if (
+          false &&
           policies.length &&
           !this.hasExtensionsInPanel(policies) &&
           !this.isPrivateWindowMissingExtensionsWithoutPBMAccess() &&
@@ -2729,32 +2734,30 @@ var gUnifiedExtensions = {
       this.blocklistAttentionInfo =
         await AddonManager.getBlocklistAttentionInfo();
 
-      let panel = this.panel;
-
       if (!this._listView) {
         this._listView = PanelMultiView.getViewNode(
           document,
-          "unified-extensions-view"
+          view,
         );
         this._listView.addEventListener("ViewShowing", this);
         this._listView.addEventListener("ViewHiding", this);
       }
 
-      if (this._button.open) {
+      if (button.open) {
         PanelMultiView.hidePopup(panel);
-        this._button.open = false;
+        button.open = false;
       } else {
         // Overflow extensions placed in collapsed toolbars, if any.
         for (const toolbarId of CustomizableUI.getCollapsedToolbarIds(window)) {
           // We pass `false` because all these toolbars are collapsed.
-          this.onToolbarVisibilityChange(toolbarId, /* isVisible */ false);
+          this.onToolbarVisibilityChange(toolbarId, /* isVisible */ false, panel);
         }
 
         panel.hidden = false;
         this.recordButtonTelemetry(reason || "extensions_panel_showing");
         this.ensureButtonShownBeforeAttachingPanel(panel);
-        PanelMultiView.openPopup(panel, this._button, {
-          position: "bottomright topright",
+        PanelMultiView.openPopup(panel, button, {
+          position: gZenUIManager.panelUIPosition(panel, button),
           triggerEvent: aEvent,
         });
       }
@@ -2941,18 +2944,20 @@ var gUnifiedExtensions = {
       this._maybeMoveWidgetNodeBack(widgetId);
     }
 
-    this.pinToToolbar(widgetId, shouldPinToToolbar);
+    await this.pinToToolbar(widgetId, shouldPinToToolbar);
   },
 
-  pinToToolbar(widgetId, shouldPinToToolbar) {
+  async pinToToolbar(widgetId, shouldPinToToolbar) {
     let newArea = shouldPinToToolbar
       ? CustomizableUI.AREA_NAVBAR
       : CustomizableUI.AREA_ADDONS;
     let newPosition = shouldPinToToolbar ? undefined : 0;
+    await gZenVerticalTabsManager._preCustomize();
 
     CustomizableUI.addWidgetToArea(widgetId, newArea, newPosition);
     // addWidgetToArea() will trigger onWidgetAdded or onWidgetMoved as needed,
     // and our handlers will call updateAttention() as needed.
+    await gZenVerticalTabsManager._postCustomize();
   },
 
   async moveWidget(menu, direction) {