Its very easy to determine how and when to feed. Again, just look at the animal in question. If an individual grows long and thin, then thickens up upon sexual maturity, THAT IS NORMAL. If an individual grows thick(fat)and not long. That is NOT NORMAL.
What causes a snake to grow short and fat is what is MISUNDERSTOOD. The common misconception with snakes is. People forget they are reptiles and think they are dealing with mammals. Mammals have a set metabolism, so food is the variable. With reptiles there are two variables. The first and most important is metabolism. The second and least important with overweight snakes is amount of food.
Metabolism is increased and decreased with available suitable temps.
The reality is, you can feed a neonate snake, daily or more, and with proper temps, it will grow long and thin and will do so very very quickly.
The simple observable traits to look for are how an individual grows. If they grow long and thin and feed readily(like a pig) your conditions and support are good. If they grow slowly and or short and fat, then your conditions do not allow proper assimilation of food items. If they are picky feeders and your conditions SUCK. Of course, non feeding can include other reasons(husbandry errors).
I did not read the entire thread, in fact, just this last post so if I repeated someone, good on U. Cheers