I used to take them out... but leaving them in the enclosure is so much better: Less stress for you and the snake, less chance of regurge from moving around, less chance of you being bitten by a hungry, eager snake...

Especially with corns, since they're so fast and eager at feeding time. Just establish a routine so you're feeding them at the same interval consistently, and they'll learn the difference between 'opening the enclosure for cleaning/handling' and 'opening the enclosure to put food in'. Also, pre-scenting really helps to establish that routine.