Those examples look OK, but it's only been a problem with clear blue skies. I did a test with the P4K Braw, X-T3 HEVC 10bit, and 5DMk3 magic lantern 14bit lossless, graded in Resolve and exported to ProRes4444, only the P4K shot has the macroblocking in both 3:1 and Q0 at varying exposure levels. It may not look so bad on a 27" screen, but I wouldn't want to risk it on a 40 foot screen. These are screenshots taken from the ProRes4444 file. Pocket 4K X-T3 5DMk3