This has been in the HDMI spec for 7 years already and most high-end TVs support 10-12 bit input. And lower end TVs it doesn't matter anyway. Also TVs often use

This has been in the HDMI spec for 7 years already and most high-end TVs support 10-12 bit input. And lower end TVs it doesn't matter anyway. Also TVs often use at least 10 bits between internal processing steps. Anyway, what you want is happening for 4k - Rec. 2020 mandates at least 10bit for 4k