I know you are writing back to the person with the QNAP, but I thought I would provide an update for the UGreen. Thanks for the suggestion - I tried getattrlistbulk (definitely a painful API :-). I was able to get it to work for a local directory, but still got zero items back for the UGreen NAS. Disappointing - I was really hopeful! I have also tried posix APIs and that didn't work either.

Sorry for the late response - I did not get a notification of your suggestion. I just tried it with iOS 27 and Developer Beta 3, but I got zero items in both cases, so the workaround did not work for the UGNAS. If you have any other suggestions for workarounds, I'm all ears!

Thank you for your answer - that helps me understand the complexity. The only point I want to make is that this issue affects macOS Catalyst apps, which do need this use case. I tried to use a AppKit plugin, but the problem is that the URL from the UIDocumentPicker is an iOS-based URL and the method is still not called in that case. If you know of a workaround using an AppKit plugin, please share it. Thanks.

This also affects Catalyst apps. I have filed FB15776793 with a sample app.