It has been my experience (if somewhat limited) that each snake grows at it's own pace. And not necesarily (however illogical this sounds) based on how much you feed it. A fellow friend followed the rule of offering untill the BP decided tu ignore the meal placed before him. His bp aprox. doubled his weigh every month for the first 6 months or so, and then it's growth slowed down, to about 30-50 grams a month.
I have to agree with you folks, after growth has slowed (perhaps 18-24months and not 3 years) we need to be more carefull about overfeeding.