We had a lot of problems trying to get the co-op to be stable enough to stream. Ended up just doing a single player+cohost arrangement.
Seems like a banger regardless.
[EDIT] Running the game through a newer version of GZDoom got the co-op stable. It has a couple of balance issues yet, but the game is absolutely a secret gem.
https://cohost.org/WobblyPython/post/1054065-memoirs-of-magic-mul
I've logged a little of what we did to make it work in a Chost.