Thread title says shameless self-promotion, which implies user-created music. The Musician forum is perfectly fine for that.
The OP talks about giving attention to obscure/fringe shit to give them more exposure. I don't really see what's wrong with GMD for that, that sort of thing is pretty much what GMD is for. Also if there were to be another subforum for obscure/fringe shit, how would we determine what is or is not obscure and/or fringe?
I don't see the point of another subforum in either case.