It seems like such a small one method change, in the context of forking an entire distro.

I wonder if PackageManagerService is hard coded in many places, rather than using XML dependency injection. If the latter then may it be possible to override the method in a subclass, e.g. MicroGPackageManagerService and distribute the change via a once-only installable zip?

That way Lineage OS doesn't need to break security, only downstream.