Something that worries me about that is attestation. This is the advice from the GrapheneOS Devs:

https://grapheneos.org/articles/attestation-compatibility-guide

They’re asking app developers to trust their keys specifically, which would mean that the app might work on GrapheneOS, but not my fork of GrapheneOS with some cherry picked fix I want.

It would be much better if we stamped this out now, before all online services require attestation.

But it’s ok because some retired boomers get to shout ‘taking our country back’ then blame foreigners for anything negative that happens

And then fly back to Spain with the sense of superiority that comes from carrying a blue passport.