It should do just fine and if it has any misunderstandings, you can correct it via something like a cheat sheet in the base prompt. Not CoPilot specifically, I don't think it allows access to the system prompt.

I found it decent for niche languages like Haskell and Isabelle/HOL.

Isabelle is quite challenging, but there is a mid-sized corpus to train on.

So I was hoping the opposite would be true, but maybe just wishful thinking.