I did this my my new pixel 8 pro. I loved it.
It was so easy, it worked, I was in control of my device.

Contactless payment didn't work.
Which is a deal breaker for me.

I looked at some fin-tech solutions, I even bought a pixel watch (which didnt work because I have a workspace account). None of them let me work around the issue. Contactless just wouldn't work.

Had to go back to stock android.
I'm constantly checking in on their attribution/verification/whatever status that would allow them to offer contactless payment (currently offered by android/apple/banks, but no open source software).
I want grapheneos and contactless so badly!