As far as I'm concerned, there are only two reasons to feed in a different container:
1. If there are two or more snakes in the cage.
2. If there is substrate that could be harmful if swallowed.
For #1, you shouldn't house two or more snakes in one cage for several reasons. If one gets sick, they all can get sick; Stress; Fight till death; etc...
For #2, a potentially hazardous substrate shouldn't be used to begin with. There are possible exceptions, as in a display cage.
There are many ways to condition a snake to reduce the risk of a feeding response strike. "Feeding snakes in their cage causes feeding response strikes" is probably the #1 misconception among new enthusiasts.
If the only time someone opens their snake cage is to feed their snake, guess what that tells the snake? Open cage = food.
Handle your snake before feeding it, making sure that you don't have prey scent on your hands. Use long tongs or grabbers to put prey in cage, not your bare hands.
You can even condition your snake by using a snake hook or something of that sort to rub the snake, to make sure it's awake and train it to know that you're going to handle it when you touch it with a snake hook.
I've got an 8-ft and a 10-ft Burmese Python I've had for almost 3 yrs now and not the first bite. When I go to feed them I open their cage and rub them with a snake hook a few times. They then come to me, crawling out of the cage to get to me. I handle them for awhile, put them back in and then feed them. I use 3-ft long grabbers to hold their frozen/thawed prey for them to take it. They don't see my hands, all they see is the grabbers and the prey.
There have been many discusiions on this in some of the forums, like the Corn Snake forum & Ball Pyhton forum. Look in these forums and search the archives of both forums for more input.
Have a good one!
Mike
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It is said that 1 out of every 4 people are mentally unbalanced. Think of your 3 closest friends, if they're normal, then it's you.