You can ALWAYS feed a bp inside its enclosure. Moving the snake to a separate enclosure just for feeding could actually give you the exact opposite result than you're looking for. Ball Pythons do just fine when fed in their normal tank/tub. Moving them to a new tub or tank before feeding will only stress your snake, which could trigger a refusal. If your snake DOES eat in the other enclosure, you still have to pick him/her back up and move back to the normal enclosure, which could trigger a regurge. It's MUCH easier to just use the one tub for everything...
And no, contrary to popular belief, feeding your bp inside its normal enclosure will NOT make your snake suddenly decide to try to eat your hand every time you open the tank. They can tell the difference between a mouse/rate and a large human reaching their hand into the enclosure.