I don't breed ball pythons, and only have males in my collection. I have never tried to manipulate a male's adult size. What I have learned is that one small rat per week will keep them fit and healthy for their whole lives. They technically never stop growing, but most usually plateau out between 900 and 1800 grams. Yes, that is a wide range, but these are living creatures and a wide range is expected. As is the occasional outlier. Had a Pastel boy that was a very fit 2300 grams.... Just goes to show you that these animals will do what they are going to do.