occtec How do I check if I have GMS installed? I thought that was something baked into the OS and can't be uninstalled??
Assuming that "Google Mobile Services" is meant by "GMS", it is preinstalled on vendor Android distributions (Google, Samsung, Sony, etc.) and not installed at all on GrapheneOS unless the user manually installs the parts that GrapheneOS's compatibility layer supports (Play Store, Play Services, Android Auto). Typically this is done via the "App Store" app, in which case the "App Store" app will indicate whether or not each component is installed.