The first boss can still be tough. I finally figured out that the closer the MC'ed boss is to the player, the more likely it is that the adds will attack the player instead of the boss. So you either want to run to the end of the room and try to blow up as many eggs as possible before the adds start spawning, or blow up eggs in the front and middle of the room until the max number of adds have spawned (60 or so, I think?) and just soak the blows.
I wonder if hunters can still cheese the encounter. I am going to assume they can but I cannot verify. Sounds like cheesing it will be easier to deal with than worrying about the adds once you know how to cheese it.