To me, "power feeding" means putting extra food into the snakes mouth just as it's swallowing the normal food item. That, in my opinion, is unnatural and bad as the snake isn't choosing to eat it, you're just forcing them to.

Now feeding until they are full, or feeding every few days, seems totally fine to me so long as the snake is choosing to eat and isn't obese. An adult mouse may be fine for the snake if it's on the small side for a 6 month old, but it will certainly out grow them before too long, unless you're feeding them multiple mice at each feeding. Personally I feed 1 rat about 10-15% of the snake's weight every 5 days.