You need to take a few steps back, you're making a very long reply to something i haven't said.

I'll be clear, i DONT like regurgitating proofs in a test, it's literally where i am most likely to lose points.

I WAS talking about solving a test question using material from another course, which is silly because that would be admitting "i can't use the tool i was supposed to practice with during homework".

Because as a problem solver, you're expected to be able to have a variety of tools to solve problems with, and you should want that, to make sure you solve problems using tools that make the solutions better in one way or the other.

On the contrary, if i allow solving a test using a different course's material then what the fuck is the test measuring? It certainly can't be used to say "this person knows how to use what i taught them".