I consistently feed my snakes in a separate container however my Spider is one of the two I have that does better in her container, the other is a normal.

I don't feed outside the container because I'm worried about aggression or them food aggressive. I feed in a separate container for my own peace of mind. I keep my snakes, except for those in QT, on aspen or Cyprus. I would be greatly upset if a piece of ingested substrate resulted in impaction or death. Live mice tend to chew, hide, or go to the bathroom while being pursued. I've even had two f/t rats have their inners squeezed out by one of the snakes squeezing too hard. Had that been in his tub, would have been a bigger mess to deal with. Keeping everything separate makes me feel like things are cleaner. If I was to clean their tubs out every time they ate I would be disturbing them far more. (*disclaimer* I don't see anything wrong with feeding in the tub for those who do and do not think separate is better in general, just better for me.) Most of my snakes have no issues feeding outside of their tubs however the spider does. I tried to feed her in a separate container but she became to stressed out to eat.

I think that if you want to feed in a separate container I say try it. It won't hurt the snake and if the snake has issues eating outside, try inside his tub. I don't think either way is right or wrong, it's all basically preference. It takes me about two hours to feed everyone (twelve snakes) between keeping the water hot and waiting for them to swallow their meal before putting them away and moving to the next one.

Good luck