No. As composition (e.g. combining subs or OSD items) happens in RGB space, there is no benefit in picture quality converting back to YCbCr before driving over hdmi.
For 10-bit output at 4Kp60, it is necessary to output YCbCr 4:2:2, so we switch to that automatically.
Thanks my friend. But when I play 4k remux, the libreleec outputs rgb. thats normal?