But what I'm trying to do is to override an existing file extension support. That's why I'm doing the import, as I need to over-ride the support provided by the operating system. An example would be Fuji's RAF file. Apple has no thumbnail or QuickLook support for the compressed RAF format. So when the RAF file is encountered, it should re-route the call to my extension instead of going to back to the iPadOS. What happens now is that Apple also broke the support for thumbnail extension on macOS 15.3 (and 15.3.1). Now when a compressed RAF file is encountered, it'll not call my thumbnail extension on macOS, but QuickLook works just fine. Apple broke it in macOS 15.1, but fixed it in macOS 15.2. Now it is broken again in 15.3 and 15.3.1. I never have any problem with macOS Monterey, Ventura or Sonoma. Sequoia is the one showing the problem. But for iPadOS, I've not found a version that would work at all. If you can show me how to modify the plist file to support say an RAF file, I'd be happy to test it. I've also filed a bug report with Apple. All they're saying is to ask the question on the forum and give them the link. I did all that, but I got no reply from the Developer Support. Seems like you guys are bouncing me back and forth without a resolution to the problem.

Anyone out there to help?