I feed f/t weaned rats (30 grams) to my juvenile bp who is just under 200 grams. He is currently being switched from 5 days to 7 days, a few feedings at a time. Hes at 6 days right now. I think he will need 30-40 gram rats to not be hungry for a full 7 days at this point so he is being worked up to that size.
The reason I feed f/t is because it is much easier for me to keep frozen rats in the freezer than live, and I have witnessed a few bites from feeding live myself. On the other hand if my bp were to refuse f/t or stop eating I would feed live.