I have a couple Orange Pi's, and the HDMI is broken. I noticed that many believe that it is Armbian, but it is not. Orange Pi's probably won't be where we want them until 2025. I found a couple notes from development teams, one below and one from September. Both say the same thing: essentially it's in the works:
"The RK3588 SoC family integrates the newer Synopsys DesignWare HDMI 2.1 Quad-Pixel (QP) TX controller IP and a HDMI/eDP TX Combo PHY based on a Samsung IP block.
Add just the basic support for now, i.e. RGB output up to 4K@60Hz, without audio, CEC or any of the HDMI 2.1 specific features."
https://patchwork.kernel.org/project/linux-rockchip/patch/20240801-b4-rk3588-bridge-upstream-v2-3-9fa657a4e15b@collabora.com/
