In https://developer.apple.com/metal/Metal-Feature-Set-Tables.pdf, it says that BGRA8Unorm format is only supported on macos if depth24Stencil8PixelFormatSupported returns true. Yet one of my MBP returns false from that property but it can use BGRA8Unorm to create CAMetalLayer’s drawable surface. Seriously, seems like the feature sets table doc is inconsistent.
I have an acquaintance who knows someone in Apple dev team. He asked them directly and they replied that the documents are wrong, BGRA8Unorm is always supported.
For anyone interested in this topic.