

It does support vp9 and h265, I believe DTS-HD as well but I think that’s only for if you use eARC (I only use optical so I have everything convert to AC3). AV1 is not supported afaik, but I have my server do the conversion in realtime with quicksync and serve up h264 or h265.
Hdcp bypass splitters seem easy to find, have you tried one? There are also hdcp converters so if you have a splitter that only bypasses 1.4, you can try hooking it up to a 2.whatever to 1.4 converter.
I also can’t remember how they work exactly but you might need an hdcp compliant display connected to the main output of the splitter so the CC can establish an hdcp handshake. Idk if that’s only a thing with some of them. Good luck!