You can get USB controlled CEC injectors for HDMI.
https://www.pulse-eight.com/p/104/usb-hdmi-cec-adapter
For a 4K120Hz TV I'd be worried about this adding signal integrity issues - "all versions of HDMI®, including HDMI® 2.0a" doesn't inspire confidence.
My understanding is that CEC can be received on any alive interface, not just the active.
Yes but you will lose 120 FPS/VRR. So for high end TVs not really ideal.
For a 4K120Hz TV I'd be worried about this adding signal integrity issues - "all versions of HDMI®, including HDMI® 2.0a" doesn't inspire confidence.
My understanding is that CEC can be received on any alive interface, not just the active.
Yes but you will lose 120 FPS/VRR. So for high end TVs not really ideal.