For PNG or PSD, Document and Picture properties cannot be used in Windows Explorer, but they can be used in Directory Opus. I've never heard in the Directory Opus manual that photo and document properties use NTFS's ADS or .ion. So, can't these two properties be used if the file extension does not support them natively? And, unlike the Extended Properties, is it possible to use it in file systems other than NTFS?
For reference, WEBP can use the properties of Photo and some Documents in Windows Explorer, but not in Directory Opus.