It seems some breeders "maintanence" feed their hatchlings. I guess by definition, it is enough food to maintain the Ball baby. I would say if a breeder hatches a baby Ball and feeds it enough so it does not looks skinny, so that it looks proportional, that is fine. Then, the person who buys the snake can feed it as much as they want.
My babies get fed two times a week for the first several months, and then once a week when they take larger prey items. The '09 PDH male I just sold was only about 50 grams smaller than my largest 09 female holdback. I knew I was going to sell the male because I have a 100% DH male, his father, but I fed him like he was staying here. I do try to feed my females a bit more than my males anyway, but I feed all my hatchlings pretty much the same. I would rather do it this way, then maintanence feed the babies I intend to sell, and have to try and pump them up right before I ship them.
I recently picked up a snake that was not quite skin and bones, but WAY under what he should have been...he looked kind of skinny and felt empty. Not cool.