The 10-15% weight rule works for me just fine because the girth is also similar. My bp is 750 grams, his meals are 70-80 grams. Anything smaller and he just hangs out waiting for more food.

Don't forget, just because prey may weigh a certain amount, does not mean it will be a specific thickness. Many rat pups or small mice can be long and thin and weigh the same as a short and fat prey (this applies more to f/t than live)

Helena, I keep my frozen f/t in a mini fridge freezer sometimes and as long as the temperature in the freezer is set to full, it is the same as the bigger freezers I have.

Anyway, a few people have mentioned prey size - that is because what you were describing as a meal in the first post was basically a pinkie, which is not nearly enough for your bp. My male would climb his vines/plants trying to get out desperately when he was a few months old, so I bumped him up to rat pups and covered his tank better and he calmed down.