User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/73.0.3683.75 Chrome/73.0.3683.75 Safari/537.36
Steps to reproduce:
Right click on addressbar
Firefox brings up its own context menu.
Firefox should follow Gnome gsettings, and either offer the deafult window manager context menu or maximize. (In gnome, there is a setting to right-click a CSD headerbar to maximize the window, which is useful because you don't have to hunt for empty space to double-click on).
Firefox's own addressbar context menu can be be presented by right-clicking the hamburger menu (or these options can just be relegated to the hamburger entirely). Everywhere else, I think it makes more sense to follow Gnome defaults.
This is the second issue I am filing regarding Firefox CSD's inconsistency with Gnome's CSD. The other one is here: https://bugzilla.mozilla.org/show_bug.cgi?id=1538481
I think consistent window management across applications is very important to the user experience.