New to the modding community. I actually had an idea for a similar balance change two weeks ago and have been working on a mod for it ever since. My version instead of +25% stress for the entire mission is just whenever the Abomination transforms, the religious get an extra 4 stress. Unfortunately I’m having a tough time implementing this due to my unfamiliarity with the toolset and, as far as I know, no other combat abilities affecting specifically tagged heroes. I’m hoping for help on the steam workshop forums but who knows.
Anyway, if you’re willing to skip the nerfing part and just want to let abominations travel with everyone, there’s a mod for that on the workshop. Just search abomination, you’ll find it quickly.