Perhaps limit bots to creating 1 open challenge at a time? (or one of each time setting)
I run RayonBot (clearly identified in name), and only ever play one game at a time, with me watching/chatting with the opponent.
I think it makes sense for bots to not be able to accept other open challenges, though I don't know if this is a problem at the moment?
Definitely in support of clearer identification of bots though.