Cage aggression. Wait but Ekans is soo friendly :(

[The Serpent Merchant]

I have 7 snakes, (4 ball pythons, 1 carpet python, 1 dumeril's boa, and 1 desert king snake) All of them are fed in their cage every single time. Not a single one has issues with cage aggression.

Cage aggression is full of flawed logic. If you think that a snake can't tell the difference between a rodent and you then you aren't giving them enough credit. A snake uses multiple senses to identify potential prey... smell (jacobson's organ), heat pits, and eye sight. unless you smell/have the same thermal signature/look like a rodent A snake simply is not going to think that you are food.

now this it not to say that you will never get bit, but if you do it isn't because the snake is trying to eat you. Most likely something that you might not even notice is different. (like with blood pythons if you move something in their cage, many times they won't eat... things that we don't notice they do. I'm not saying that cage aggression is 100% impossible (as you said in our universe there are endless possibilities) but it is improbable.

You are much more likely to get bit feeding a snake in a separate container since you have to directly handle the snake right after eating, to put it back in its cage.

Your plan is a good one, try feeding in a separate container, if it works, great... but honestly I doubt that it will.