One thing you have to keep in mind is that these arn't wild snakes so you can't feed them like wild snakes. Wild snakes arn't stuck in a box so they are less prone to obesity. They may eat three rats in one night but then go half a year without eating again. Also, snakes in the wild don't live half as long as captive BPs on average, if that. Its mostly due to predation, but I bet irregular meals contribute.
I think it is a bad idea to feed any snake until it refuses a meal. This may work for one snake, but how can someone say your snake won't gorge itself to the point of regurgitation or even death?
The majority of breeders suggest feeding every 7-10 days on a regular basis because this has been shown to promote longevity and health in the long run. If you start feeding your snake randomly there is a good chance it may start fasting.
I read a good post on why its good to feed BPs regularly, but I can't remember what it said. It was something about the motabolism and such. Try to get some info before you start experiementing with unorthodox feeding regimens.
-Austin