Fullscreen controller scales based on combined screen area
I've discovered why some people report "the fullscreen controller is way too big! I'm on a 1920x1080 screen!" and others report "the fullscreen controller is perfectly sized! I'm on a 1920x1080 screen!"
Turns out the difference between the above two statements is not in their resolution, but rather how MANY screens they have.
Two 1920x1080 screens side by side are seen as 3840x1080 by VLC and it then picks the HUGE (oversized) fullscreen controller.
A fix would involve a check of "what screen does the video playback reside on? what is the resolution of THAT screen?" rather than just querying Mac OS for the combined desktop area of all screens.