Is using Citra allowed? And if so, are we forced to play the most recent update with it?

Sorry for a late response on this, being that emulators are weird with different games, it's possible that citra could speed up the game/game's loads like how NTR on homebrew new3ds does. I've never actually tested citra before though (or used it myself for that matter). It's definitely something to look in to, but unfortunately for the time being it'd have to be banned. I wouldn't get my hopes up though on it being allowed in the future.