Same etiquette I use in my apartment building's laundry room, LOL. Haven't owned a washing machine since my kiddos were young and have never owned a dryer.
If the clothing are dry and no one is around I put them in an avail bin or on the folding table. If the clothing is in the washer and finished then into a bin they go. No waiting around for someone to come get their stuff 'cause obviously I'm busy too:W. Also in general no attitude from the person who is late; did them a favour and they don't have to bend down to pick up their clothes.
Never seen a laundry room confrontation. Hope it's all good clean fun though.........