I think that the reason that many of us want to steer people away from breeding smaller females is this. We don't want relatively new breeders thinking "oh, I just got this hatchling female this year. Why don't I powerfeed her and breed her asap?" People that have experience and that can read their snakes, can safely breed smaller girls; that is proven by their postings of doing so successfully. But I don't think that this is something for a beginner to get into.. because they might have trouble seeing signs of bad sheds, parasites, and the like.. let alone, have trouble determining if a young female is ready. Now if it is a potential breeder who's already had BPs for awhile, and knows how to tell if they're in great physical condition.. maybe IMO. I am glad that breeders suchas JAS that have success with the smaller-than-1500g girls are coming forward. I admit to being against it in the past, but after seeing people with more experience than myself doing it, I think that it is definately a valid practice.
Isn't it true also.. that if a female is not ready, she won't produce eggs anyway?