Imo 3...Bb4+ doesn't make any sense if White can answer c2-c3 (as opposed to the Bogo-Indian(3.c4 Bb4+), and 4...Ba5 totally misplaces the bishop. I guess that 4...Be7 would be better despite the obvious loss of tempo, but on the whole I think Black needs to find a better 3rd move, possibly 3...d5, 3...c5, 3...Be7 or 3...h6.