> Making it system-only still isn't ideal. It then requires a full OS update to push updates to microg/playservices
It does not, you can update system-apps out of band just fine.
Google does it with Play Services (and many other apps), and we have our microG builds in our F-Droid repos for out of band updates.
In fact, that is one of the big selling point of Play Services - the fact that it gets updated outside of OS updates, which means that you have a recent / the latest version on all devices regardless of their update record.
And therefore anything implemented in Play Services can be used even on older Android versions.
It does not, you can update system-apps out of band just fine.
Google does it with Play Services (and many other apps), and we have our microG builds in our F-Droid repos for out of band updates.
In fact, that is one of the big selling point of Play Services - the fact that it gets updated outside of OS updates, which means that you have a recent / the latest version on all devices regardless of their update record.
And therefore anything implemented in Play Services can be used even on older Android versions.