I use #ZenBrowser where I have vertical tabs (on the left), and I use the #Bitwarden addon which is set to display in the sidebar on the right (so it stays open when I'm logging into sites, etc.).

I recently tried #Waterfox as I've heard good things about it, but it seems my setup in Zen isn't possible here... Vertical tabs display in the sidebar, so I can't separate tabs and Bitwarden to the left and right of the screen respectively.

Am I missing something, or does Waterfox not support this?