Handling your snake on feeding day isn't a very good idea.. it's best to be avoided.
Also feeding inside your enclosure for ball pythons is highly recommended and I have a few reasons why.
- Ball pythons are very shy animals, and because of this they don't want to be picked up and have a mouse or rat shoved in their face in a completely new and unfamiliar enviornment.
- Ball pythons prefer to 'hunt' or 'prowl' their prey. They get the chance to do this when fed in their enclosure.
- Moving the snake after eating could cause regurgiation and stress.
- People think that feeding in a separate enclosure prevents them from associating your hand with food. This couldn't be further from the truth. Unless your hand smells and looks like a rodent, they are biting at you for a different reason then food. Usually when people feed in a separate enclosure, they have a much higher chance of being bitten before or after the meal then if the snake was in the enclosure.
- Consuming a bit of substrate also tends to be a worry. If your snake eats a bit of it's substrate it should not be a problem and probably never would be (unless you were using sand), as the substrate would just pass through their system harmlessly.
Just my 2c.