Apps in the private space show up in a separate container in the launcher, and are hidden from the recents view, notifications, settings, and from other apps when the private space is locked.
r134a Hmm, only when locked?
I feel like this might be an important distinction.
Thinking about this from Google's perspective, they would probably want apps in the private space to be able to communicate with Play Services in the owner profile. If that is the only exception, that is probably prevented on GrapheneOS by running Play Services in the sandbox.
Or would they design the feature in a way that communication is enabled with any app in the owner profile when the Private Space is unlocked?
The developer docs seem to emphasize the use-case of keeping apps hidden from shoulder surfers, snoopers, or someone borrowing your phone, which is probably not the primary concern of GrapheneOS users.