Oh well, it was too good to be true, I have this flickering issue too on my LG E6 OLED TV.
It’s really hard to capture but in this scene it’s pretty unbearable: https://www.youtube.com/watch?v=kAlVEVkKeO4
It can be seen around Halle Berry’s head in the light areas and it’s much worse than it seems on youtube.
Here’s also my log, although the issue should be rather clear now: http://paste.osmc.io/hubucekaqo
If you use the aforementioned workaround make sure that the setting “Adjust frequency” under Playback is turned off, else the script won’t have any effect. For now I’m turning this setting off whenever I watch a 4K movie and turn it back on afterwards. Unfortunately I didn’t find a way to change this particular setting via the Kodi callback addon. Maybe it could be introduced as a special option until a real solution is found.
It’s really just a workaround and I hope @sam_nazarko is still on it. I would consider going for the Apple 4K but that doesn’t have a chance of getting packed 3D playback at any point so I’m hoping for the continued strong software support for OSMC.