Hi,
In solo mode, the inventory menu allows to drag'n'drop from one character "bag" to another. That's great !
But in multiplayer sadly it doesn't work that way. To do this, I have to drop the item to the other player's character portrait (which it's much further) or right click, send to Dumber.
I know that's not such a problem, but that's annoying (I always forget) and a time loss in the process.
Currently, my friend is the one who barters, so I'm the one who marks as garbage (shift click it's fine) and also the one who drags and who drops...
Further now, something like alt + click could open a pop up like "to who would you like to send that stuff ?". That thing could be smart enough to send directly to Dumber if it sees that we're only two - Dumb isn't dumb enough to send something to himself.
Furthest (does the word exist ?), let's combine both current maj and hypothetical alt "send that garbage to ..." with the smart thing and you'll make every lone wolf duos happy.