My tv is 4K but my av receiver is not. So I want HDMI 0 to go to my TV and HDMI 1 to go to my av receiver for sound, it doesnt even need video on second HDMI.
I found comment by popcormix from over a year ago say its possible on hardware level. I wonder if now maybe it is possible?
I think this is possible from a hardware perspective.
We'll need a way for kodi to choose a different hdmi port for the audio
(possibly a different Sink, or maybe just a config option).
Don't hold your breath - there are more important things to support first,
but it's something I'll bear in mind.