The german translation for Settings -> Screen Mode -> Borderless Fullscreen is - in my eyes - kind of misleading. You are not removing the borders of a fullscreen view, because there are no borders in fullscreen in the first place. You are much rather removing the borders of a window. Instead of the german translation “Vollbild ohne Rand” I would rename it to “Fenster ohne Rand”. I might interpret it in another way and just not get your point of view, though.
I saw that there are a lot of translations missing. You migh as well just send me an e-mail containing something like a excel sheet with all the missing translations. I’d translate it.