After watching "Leverage multiple displays and scenes on iPhone Duo" and "Build a great camera experience for iPhone Duo", we have four questions about the outer display while the device is open: Does a view hosted in CameraCaptureAccessory receive touch input on the outer display, or is it display-only? The accessory is described as available when the app "has an active camera session." Does that require a running preview layer or an attached output (photo, movie or data), or is a running AVCaptureSession with an input enough? Is a session whose main purpose is to host the accessory a supported use? Can AVCaptureMultiCamSession run the inner (under-display) front camera and the outer front camera at the same time on iPhone Duo? If so, which device-type combinations are supported, and are there thermal or power limits? Is CameraCaptureAccessory the only way for an app to show content on the outer display while the inner display is live, or are scene accessories that don't depend on the camera planned? Our use case is not photography. We're exploring a companion view for a second person sitting across from the device owner, so we want to understand whether the camera accessory is the right tool before designing around it.

We're designing a two-person layout for iPhone Duo. The device lies fully open and flat on a table between two people facing each other. The inner display is in portrait orientation and split with ArrangementView using the default .split style, which stacks the regions in a tall window. Each person gets the half nearest them, and the far region uses .rotationEffect(.degrees(180)) so it faces the second person. The hinge isn't used for layout. While iPhone Duo lies fully open and face-up, does the interface orientation stay stable if the device is nudged or turned on the table? Is there a recommended way to hold it steady for one screen without restricting orientation app-wide? Is rotating one arrangement region 180° a supported pattern? Specifically, do the reserved regions from GeometryProxy.reservedRegions(kind:options:) need to be converted into the rotated region's coordinate space by hand? And do VoiceOver hit-testing and the focus ring follow the rotation? In an immersive full-screen view in this posture, can the status bar be hidden? If not, what's the recommended handling of its occlusion region, which would appear upside down to the second person?