RK3588 HDMI Input - 2160p60 4:2:0 only?

Hi all,
I want to use the HDMI input on RK3588 with v4l2 at 2160p60 resolution. This works fine except that i get only 4:2:0 pixel format, .i.e. ioctl(…VIDIOC_G_FMT) returns NV12 only. Instead with 2160p30 I get multiple pixel formats including RGB24.
This would be HDMI 1.4b, not HDMI 2.0.
Has anybody got 2160p60 with RGB 24-bit (or YUV 4:4:4) to work on the RK3588, under either Linux or Android?

As per (Rockchip RK3588 TRM V1.0-Part2 20220309.pdf)