@CubeLogic, consider the following scenario. You are up 1 second, and a pawn mates your partner. Your opponent has just forked your pawns. What do you do?
Obviously, you sit. But this could have potentially catastrophic endings for your team where you flag instead of your partner's opponent
I think at least for me playing with this rule addition would be more streamlined with premoves already in place.
@TheMutatedDonkey has raised a point that initially I was worried about: in their scenario where one player must wait down the time to keep pieces from their partners board is one that already exists without premoves, and the premoving off the side of the board would be better for the side with the missing mating piece, these games usually come down to a time scramble where the checkmate is forgotten and it's a fight to keep seconds on the clock - and because of that I don't see this new rule actually making these situations completely different at all.
The one clunky thing about trying to play fast is dragging pieces off the side of the board without premoves in place at least for myself and likely many of those who like this idea.
I'd love to see this added though - unless someone completely changes my mind 
On FICS, it was possible to right-click on a square and select a piece that you wanted to drop on that square. If you didn't have the piece it would drop the piece as a pre-move. Mostly this was only relevant in games where you could pre-move a mate just before flagging, which isn't very common. But I do think that being able to right-click on a square to drop a piece in bughouse is a neat feature that I would love to see on chess.com.
actually, upon further analysis, i believe i should be giving a -1. Time is a paramount factor in bughouse games, and assisting those who are only 1 second or so down is not upon my playbook
No it would assist people who are up on time.