When my first BP was little, I used to take her out of her enclosure to feed her in a shoebox tub. Now that she's bigger, and I now have multiple snakes, I feed them all in their enclosures, and I have yet to be bit by any of my snakes. It really all depends on what you want to do. If you set up a routine and stick to it, feeding your BP in a separate enclosure wont cause any more stress than feeding in the enclosure because they have become accustomed to it. Just make sure to 'hook train', or pick them up the same way every week, at the same time, so they can get a schedule going. Just be aware that you are taking a higher risk of being bit by picking up and moving a hungry snake.