I don't mean that 2+ people play the game at the same time on a server. I'm asking whether or not 2+ people in the same room can switch out between 1 character. An example of this would be if Joe does 1 part of the run, then Joe passes the controls to Bob, who does another part of the run. Just wondering if that kind of thing is allowed.

I would guess no but I'm not 100% sure.

I mean technically no one would really know, idk how much this would help

I think you should default to no. You'd have to discuss with the community of any run that you want to perform. I do love this idea though. There are a lot of games that would be interesting with a codified tag team category.