I'm unable to edit a lot of things in Finale Notepad, such as supporting multiple key signatures and smartly changing the number of measures in a system (i.e. without creating one-measure systems).)
I failed to notice a crucial two-letter word. My bad.
I got a bit confused because you mentioned:
I'm speaking as a Musescore user who exports MusicXML files and sticks them in Finale Notepad.
Which made me question why you even talked about:
supporting multiple key signatures and smartly changing the number of measures in a system
Because you can do that by exporting MusicXML files and sticking them into Finale NotePad without fail.
Sorry for pointless chatter lol.
Regarding the actual submission, although you can
format without the full version of Finale (complex XML editing), it's just easier to either have Finale, or get a person who does to format the sheet for you. If it's just in your Personal Arrangement Thread, then it doesn't matter. Only when you need to submit a sheet to the site do you need to go through this simple process, so it's really not that bad.