I think most BP will eventually fast if given more food than they can use for good growth at a given time.
I also think that unless you have a 1 in a million BP, all you're doing with limiting their food to control their growth is limiting their food.
They won't eat if they don't want to. They're not corn or king snakes who will hit food just because it exists. They eat to grow. They're not reluctant to refuse. Trying to limit their growth just seems like pure silliness to me. UNLESS you are seeing signs of OBESITY as opposed to GROWTH, but again - that's that one in a million BP. They don't get fat easily.
Just how much growth was it you saw that concerned you?
(I feed once a week.)