@Craig_Holliday I can’t explain it, but under the latest 8.45 release with the same movie I’m not seeing the extreme blowouts and colors on either my DV/HDR set or SDR set. I know you mentioned only PiP and audio sync were worked, so I’m not sure what to think. Things seem to be on the edge of blowout and don’t look as natural as Infuse, but it’s definitely not as extreme as what I was seeing.
However I am noticing one odd thing on at least one of my DV/HDR 4K sets with latest ATV 4K. I configure the “TV” button on the Apple remote to return to the Home Screen rather than TV App. If I’m watching a movie and hit that button, it goes to the Home Screen but I can hear the movie still streaming in the background. If open Plex again video shows instantly, basically confirming it continued to stream in the background. This is repeatable every time on that set. However this doesn’t seem to happen on the SDR set I just tried which has the same latest 4K Apple TV.