and its core, immutable filesystem cannot be edited

That's a half-truth at best; I can just open the disk image in a hex editor if nothing else understands the format.

Hackintoshers have figured out how to add/modify drivers etc. It's certainly not without obstacles, but that's still very far from "impossible". If I remember correctly, you need to re-snapshot the FS and tell the bootloader to boot from it.

(And necessarily, ignoring the countless cries of "it can't be done" was how I was able to accomplish my goal... I knew that it was possible since I could edit any bit of the FS; figuring out which files I could remove and patch was the hard and undocumented part.)