I will know from some experst here what is the influence of clear HDMI out and get record prores on ninja
According color grading vs recording directly ALL-I
After a research I answer mine question:
8 bit is 8 bit when you get via ninja to prores 4:2:2 8 bit or 10 bit it doesn't matter the source is 8 bit
There is not much difference in grading 8 bit 4:2:0 or 4:2:2 the problem is 8 bit if you want better color grading options you have to move on 10 bit or more..
So the firmware update of 5D mk3 HDMI out is only for better workflow