If possible, are emulator 3DS MSF2 runs allowed to be submitted? If yes I'd like to know a few things:

Which emulator, settings, game version (if applicable), etc

Or whatever other rules and limitations must be applied. Wouldn't​ want to accidentally break some kind of rule. Thank you.

I'm not a mod for this game, but familiar with the series and games.

I don't see why not. Run is measured IGT anyway. I just have no idea which emulators run the game reliably. I don't believe there are any language differences. Perhaps asking the WR holder would be good, not as to imply they should gate other submissions, but as to suggest they are more knowledgeable about the quirks the game has (considering this game doesn't see much activity).