If you really want to put restrictions on it, why not just restrict the number of times a player can qeue for roulette per day outside of being vote-kicked. That way if the player wants to spend all their tries shopping around for the perfect party or the right dungeon, then they can deal with losing their chance at reward if they abandon one too many times. That way players aren't being directly penalized for abandoning futile situations or because rl throws something at them, but they are being deterred from making a habit of shopping around and then rudely dropping for next to no good reason. Vote-kicking/being vote-kicked doesn't need to be restricted at all, because the system can be abused and who wants to be penalized for trying to give helpful advice when some noob doesn't want to hear it.