CHANGE HAMBURGER MENU - User Control For Application Menu Sections
Mozilla and Firefox Team: Over the past 4 years - your user community has been asking for a way to CHANGE RIGHT SIDE MENU (hamburger) 'Application Menu.' The coding Mozilla uses ... make this Application Menu flexible for users please?
ALSO - major cleanup any false search results on this issue - useful details on HOW TO CHANGE THE FIREFOX hamburger, application menu, context menu, right side menu. After you make the change and make this menu user friendly - please sweep old support inaccuracies.
Opaite Mbohovái (1)
Mozilla recently started up a new "Ideas" site at https://connect.mozilla.org/ to gather product suggestions. I think if you have time, it would be a good idea to post there (or add Kudos to an existing "Idea") to get into the current feedback stream.
For now, as you have noticed, there is no built-in feature to change menus. You would need to use custom style rules in a userChrome.css file. This is a community-supported (not officially supported) method. You might get some comments here anyway, but otherwise, try r/FirefoxCSS on Reddit: https://www.reddit.com/r/FirefoxCSS/