possible to coop online or not?

The rules say that “Two players each beat the game on the "2 player game" mode on one console.” So it can’t be performed online

Netplay? It's allowed in smb3 coop.

same thoughts with windward. i know there's a bunch of runs in the leaderboard that do netplay on nestopia

Yea apologies about that, the rules didn't make it clear that netplay is considered OK as we already do have submissions which use NSO for netplay.