I know for a fact based on my own experience, that Kill The Leader (KTL), is allowed, even if the leader is piled with the lowest health worm. If the host or anyone else, would get mad if you as a leader would pile their worm, even if it would endanger their participation of the game, then that's their own problem. Though, if anyone would pile a low health worm, it could be seen as a ''dick move'', but that's open to interpretation. Some just want to end the game fast, and some are genuinely not great people.