After switching to "plaintext only" message composing in settings, the formatting toolbar is gone, and no setting it back to HTML compose or any other menu option or setting could bring it back.
The only way to get it is holding Shift down while clicking "New Message". Ctrl+Shift+n does not work.
In my opinion as soon as html message composing is enabled in the settings, the formatting toolbar should automatically appear and it should be possible to toggle it on and off in the View menu.
Also it wouldn't hurt to have a right click option to switch between HTML and plaintext composing.
Version is 115.6.0 (64-Bit) under Mint 21.3. I am using the German translation of Thunderbird, so the settings may be called differently than what I named them.
