i think the professional breeders have quite a strong incentive to keep an optimal feeding regiment, simply because people pay more for well-started babies, and for subadults people pay more if they have more weight.
so when it comes to cutting corners and cutting costs, it will likely be other things, like enclosure size, substrate, hygiene.
adults can get overweight, but babies grow out of it or make up for it by growing faster.
edit: oh, an how i feel about it? i think they should be fed every 5 or every 7 days. you can feed less by feeding smaller size, but im not a fan of these random gaps. im also not a fan of powerfeeding BPs up to breeding size in the minimal amount of time possible.