I had a bit more time for testing today.
Unfortunately Krypton is still not an option for me.
Does the dev build represent the best possible Krypton right now or are my issues maybe linked to this build and don't exist in 8.0.1e?
Here is my list:
Advantages of Krypton dev over 7.0.3.012j:
+ No "dark GUI" before a video is played.
+ Left edge overscan is gone.
+ 59.94 fps video plays hardware-accelerated.
+ 23.98 fps, 29.97 fps and 59.94 fps are available as GUI refresh rates.
Problems in Krypton dev, which do not exist in 7.0.3.012j:
- High bitrate 1080p videos (e.g. BD remux with DTS-HD MA audio) trigger random frame skips.
- High bitrate UHD videos (e.g. various Samsung/LG/Sony demo videos) trigger random frame skips and random black screens.
- HDR videos keep triggering the TV's HDR logo after the black screen as if the video stream is completely lost and then picked up again.
- The black screens seem to be limited to "higher" refresh rates (29.97 fps, 50 fps, 59.94 fps and 60 fps). I did not see black screens in the Samsung HDR Wonderland clip, which is 23.976 fps.
- There seems to be a bit of an input delay when navigating the GUI and video overlay.
- In some videos a/v seems out of sync, I have not figured out a pattern yet.
- Random remote inputs kept being triggered (e.g. page up/down or back) although none of the buttons were used (external MCE USB remote). I worked around that by using the box's remote.