That about:config setting is a halfway okay solution for a single app, it loses vertical space however, which is my premium. Optimally I would like a way to (in all applications which has this problem) to _simply show me_ what is a UI widget/button and what part is "inert" draggable window chrome, like this older screen shot where the distinction is unambiguous and clear:

https://i.stack.imgur.com/Se6i0.png