It would be nice to have a setting for automatically closing a poe trade window whenever that person leaves the party.
You can say "Thanks" then remove them from party which will remove the window but lots of times for me; people join and then leave without trading (notably in currency trade).
you can manually remove them right now but it can get tedious.
Hopefully this would be a keybind to toggle this function on and off. Just a setting would work too.