i would think that adding more mice into a feeding is still powerfeeding. your not feeding multiple times a week but your feeding more so IMO it balances out to be powerfeeding.
be careful when you put the mouse in with you snake fluffy, before you know it the snake will strike and the mouse can bite the snake. When im feeding i hold the rat by the tail to get a headshot. If the rat were to bite the snake still I already have my hand n the enclosure to stop it
I dont think you would really have to worry much about losing a breeder by breeding it at 1200 grams. The bigger the better, you can get more eggs from a bigger snake