Turn menubar into classic Firefox style button

[the-r3dacted]

It would be cool to have the menubar turn into a classic Firefox style button in the top left. Then when maximized it moves to the same row as the tabs like the button did historically. I can't find any themes that do this nor am I sure how I would accomplish it, but it would be cool to have.

[RalphCZ]

Echelon (download from source code, there is updated version for 128 ESR, also remove or rename echelon_bookmarks_menu.uc.js in chrome\JS\ folder to make bookmarks working correctly)

[the-r3dacted]

Doesn't Echelon move the hamburger menu into a button? I'd want the menu bar turned into a button.

[RalphCZ]

Doesn't Echelon move the hamburger menu into a button? I'd want the menu bar turned into a button.

On classic themes it makes button on titlebar/menu bar, on australis themes as button on toolbar