Removing ~half of the code to check if that makes it compile (even if it will error afterwards) a few times wouldn’t take too much. Perhaps also watch if the server window says “updated (script name)” and what the Output window says / add screenshots of these.
Global variables should be fine; there might be some way to break globalvar detection if you don’t use semicolons or find a novel way to write the declaration that I’m not aware of (e.g. the extension used to have problems with var var i;). I think the most notable issue right now is that trying to live-update a constructor doesn’t work very well, only methods inside it.