That’s great, but the sandboxed Google play services are by default set to normal in battery usage. Meaning it’s subject to dooze and other ways to artificially limit its background activity.
You neee to set the battery usage to unrestricted to reliably revive notification.
I wonder what the packet count would have been with unrestricted Google play services.
The data I really care about protecting would fit into a few kilobytes, so knowing the phone sends, for example, a minuscule 2 MB/day, brings me no comfort.
Obviously they send back this data to Google, for legitimate and advertising reasons. For instance, how would they backup apps you have installed if they didn’t know what you installed in the first place.
On grapheneos, it doesn’t have access to this data, but it can still gather a lot of data (just as regular apps on Android). Location (even without location permission), WiFi devices around, Gyroscope so they know if you are standing, driving or else, etc…
Android is rotten to the core.