Actually I think you're the first person I've ever seen argue that a separate enclosure encourages cage aggression.

There are mixed schools of thought on the separate enclosure idea.

Pro-beliefs:
  • The new cage is different and the snake associates it with feeding, so the home cage doesn't become a food zone
  • The new cage can have a more dinner friendly bedding(if any)
  • cleanup afterwards is usually easier(if it's necessary)


Con-beliefs:
  • The transfer into/out of the food pen can be stressful and discourage eating
  • The lack of familiar hides may make the snake less likely to eat
  • Reaching in to a hungry snake cage may trigger a bite.
  • The lack of heating makes slow eating an issue(or requires the purchase of more heating devisces)


Not all of the Pro's/Con's have been proven(some probably never will be) but that's the most common/strongest arguments each way. It's up to you ultimately, either way usually works fine in the end.