One other issue I am seeing (and I have filed FB12470856) is that the PHAsset.mediaSubtypes value is not correct: The HDR badge is not shown for either my gainmap HDR photos or for the ISO HDR photos. In my code the PHAsset.mediaSubtypes value does not have the PHAssetMediaSubtypePhotoHDR bit set. Instead the undocumented 0x200 bit is the only bit that is set. Seems to me that the 0x200 bit needs to be documented or the HDR bit (PHAssetMediaSubtypePhotoHDR = (1UL << 1)) needs to be set.

Yes, the APIs do appear more more functional now. I have some Apple Gain Map HDR photos on my camera roll that I took with the camera on iPhone 13 Pro with the iOS 17 beta installed. I also was able to get some of the Apple ISO HDR photos onto that phone from sample code for the WWDC23 session: https://developer.apple.com/documentation/uikit/images_and_pdf/supporting_hdr_images_in_your_app?language=objc I am now able to see the HDR effect in my app using the xcode beta two build and iOS 17.0 (21A52688h). Thanks.