yes, there was a bit of a controversy/debate about it ages ago but now its allowed, this was likely actually the same for other games, and I think the current WRs now use it?

it used to be a separate category because Ozotuh was an idiot, so prnced on a dead run decided to add in second player at the very end for a free meme WR

Current record does use 1p2c strats mainly for dupes.