We use an invite exclusion for the IRC bot based on a cloak that gets applied after the bot identifies to NickServ. The bot seems to try to identify, then join the channels before the network's services can apply the cloak, keeping the bot from joining the channel.

It would be nice if the bot could wait for notification from services (I can't think of an IRC network agnostic way to do this), or at least sleep for a period of time after identifying to services.