the communication permission work for me with xcode and ios 26.2 public release
it needs sync contacts and enable communication limit on the child device.
the error messages I got from console were very helpful.
(501) Invalidation handler invoked, clearing connection
(501) personaAttributesForPersonaType for type:0 failed with error Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.mobile.usermanagerd.xpc was invalidated from this process." UserInfo={NSDebugDescription=The connection to service named com.apple.mobile.usermanagerd.xpc was invalidated from this process.}
SendFlow (Host): Error sending begin message: hostViewControllerDidActivate(_:) Error Domain=AskToCore.ATMessageComposeValidationError Code=2 "Contact syncing is not set up" UserInfo={NSLocalizedDescription=Contact syncing is not set up, NSLocalizedFailureReason=Contact syncing needs to be configured before you can send messages., NSLocalizedRecoverySuggestion=Please enable contact syncing in Settings.}
SendFlow (Host): Error sending begin message: hostViewControllerDidActivate(_:) Error Domain=AskToCore.ATMessageComposeValidationError Code=3 "Communication limits are not enabled" UserInfo={NSLocalizedDescription=Communication limits are not enabled, NSLocalizedFailureReason=Communication limits need to be enabled before you can send messages., NSLocalizedRecoverySuggestion=Please enable communication limits in Screen Time settings.}
However, I still don't know how to fake my location to texas to test significant app update