Minsc is not going to become any more fleshed out than he was in BG2 -- he's a big, dumb good natured one line factory who looks to others for guidance. He a good friend, someone you know he always has your back. If you flesh him out too much you ruin him.
If Minsc is actually in the game, I hope he's not a playable Origin character, because the main story seems to be based on whether the MC chooses a dark or light path with the tadpole.
That's not Minc's personality at all. I would use him in a heartbeat as a companion, but not like that.
