The latest update of Firefox has seemingly made the "List all tabs" button unable to be removed from the tab bar like it was previously. I request that this button be made optional again.
Failing that, I request that it be moved next to the close, window, and minimize buttons, instead of having a blank space between that button and the window controls, or that it be anchored next to the New Tab button. I think it would look much nicer if it was not out on its own.