I used to feed everything out of their enclosures, because I thought it would make them less cage defensive. But I started getting sick of having to get all these snakes out to feed them, so I stopped doing it to roughly half my collection. Then I started to notice something.
The snakes that I handled a lot, some were fed in their enclosures, some were taken out for food, They all stayed friendly.
The snakes that I used to handle regularly but had almost completely stopped handling, had started to become snappy and cage defensive, even though some were still taken out to feed.
My verdict, after years of experience in this area. Is it makes no differance where you feed your snakes, it all comes down to how often you handle them.