If anyone has a suggestion about where to download sub-1-minute ProRes 4K footage, it would be appreciated. I've only managed to download 4K Flash video off YouTube with 4K Video Downloader. That clip works fine in Premiere and I can even apply unsharp mask to it and play it back smoothly. I did a test render out to 1080P from it and that turned out fine.
The next step is to test with actual ProRes 4K footage. Where can I find it online in its native format?