in nsmb theres a category just for emulators which would be interesting in nsmb2 as recording a 3ds its a bit hard. Since loading times are differents I think that a category for emulators would so good.

My 3ds has died and I want speedrun the game :(

Citra is very inaccurate so I don't think that will be a thing for now.

A 2DS is only like $50 if you need a new system.

^What R0main and Pear said. Also, even if you can't submit to the leaderboards, no one is stopping you from running the game on your own.