They can eat large prey items, But just because they can dont mean they should. Large meals is wasted food and money. You will notice if your feeding too much if your getting massive poops more often.
I been doing this a long long time and I get females up to breeding and laying eggs before their 2 years old. I dont power feed and i never feed a rat over 50-60g per week. Smaller meals more often gets you better results and keeps a consistent feeding than one large meal a week.
This 10-15% rule is a forum thing That surfaced, why I dont know but its not to be followed for every snake. If you want the snake to grow fast and fat, feed large meals, but keep in mind the snake will also slow up on eating later on to catch up to the larger meals.