I bought a second hand Pixel 7 to test this and an exFat SanDisk Extreme Portable 2TB works with reads/writes perfectly.

Does this require installing google play and other google services to work?

Edit: https://grapheneos.org/usage#android-auto

Does that require being logged into a Google account? How to ensure Google knows nothing about your shares?

I have Graphene w/ Google Play Services (required for my job) and would love a easy way to share files/info with various devices (incl. iOS/macOS which I remember should work with QuickShare in the future) but will avoid a service that shares data with Google.

Pixel are supposed to be very good in photography, part hardware and part software, and my concern would be degradation of that software part. With small kids, there is nothing more important on phone for me than photos/video quality these days (apart from never going into apple ecosystem, I am just incompatible with that company' philosophy).

Or its just about slapping some commercial photo app (like I heard from other photographers is often done on apple to get most out of it, but forgot the name of the app) and not caring about this?