Thanks a lot for the info.
Do you know by a chance what information apps can exchange - is it personal info or just generic telemetry rubbish? Lets say an app doesn't have any built-in trackers (as reported by Exodus app), does it mean it can still communicate with other apps and exchange info?
I wonder if push notifications always use the same address to dial in home - in this case we can block all other traffic from the GSF and only allow traffic to that specific domain for push notifications only (I am using AdGuard Home/DNS so can configure that).
The wallpaper part is tricky - I also watched Side of Burritos' videos (a great channel by the way!) but then followed his advise and turned off Enable Native Code Debugging which broke banking apps and PayPal app. So I thought maybe the issue with wallpaper fingerprinting is just a theoretical possibility not something we need to be concerned about. So this part is confusing.