Not eating for 17 days is... nothing for a healthy ball python.
And as you're discovering overfeeding them is just about impossible. They tend to self-regulate. They may eat a lot in one go for a little while and then fast to make up for it or just refuse if you offer more. They aren't dogs, or even corn snakes. They aren't going to eat more than they want or need.
"Fastest way to grow" is to feed appropriate sized prey on an appropriate schedule They will grow as fast as they grow and you just have to deal with it.