This post is from the Activity iPhone Duo Photos & Camera Q&A.
When iPhone Duo is fully open, so the outer front camera and the rear cameras face the same direction, is there a virtual AVCaptureDevice whose constituentDevices include both the outer front camera and the rear 48 MP wide camera, so that virtual device constituent photo delivery that could produce one photo from each of those cameras simultaneously, as is possible on existing iPhones with two rear cameras, using isVirtualDeviceConstituentPhotoDeliveryEnabled / virtualDeviceConstituentPhotoDeliveryEnabledDevices?