I have "Hide system window titlebar" checked in Settings -> General -> Language & Appearance, and it works well on the main window (after using CSS to move the Thunderbird minimize/maximize/close buttons back up to the top of the window, that is,) but it doesn't seem to be working on the Message Compose Window. The system titlebar is still there.
Is there a way to make "Hide system titlebar" work on other windows besides just the main window?
