I’ve done something similar trying to get root on Graphene OS, since I’m more far more concerned about corporations than nation-state actors. It can be done, but isn’t worth the trouble, especially since it doesn’t completely work and GOS updates may break it. Long story short, GOS wasn’t for me.
For anyone else who might be interested in trying to root GOS, take a look here: https://github.com/schnatterer/rooted-graphene I believe this to be likely the most comprehensive source for getting started.
Yes, that’s right, so I did. I wanted to have a go to see what it was about, though, and I found that root was more important for me than the security that GOS purports to offer.
This was what I learned.