Tab Shortcuts - Pinned & Unpinned от SAGYO

Change the shortcuts from: about:addons > ⚙️ > Manage Extension Shortcuts

• Navigate unpinned tabs with Alt+Number by default.
• Pinned tabs have no new shortcut by default.

You can assign Ctrl+Number as hotkeys but behaves a bit strange.

Zen Browser

Firefox extensions can't detect if a tab is essential or not, so you have to manually set how many essential tabs you're using by clicking the extension's icon and modifying the value in the popup.

• Essential tabs have no new shortcut by default.

You can assign Ctrl+Number as hotkeys but it's recommended that you change these hotkeys from Zen's settings first.