Just FYI. While I was experimenting I purchased a magewell 4K HDMI encoder box that does multi-channel audio, including DD 5.1. It actually worked great, but two issues make it not a viable option. 1. It is expensive. I don't remember exactly, but it was north of $500 IIRC; and 2. I could not get the HDCP to be happy unless it was connect to an older ATV (non 4K). Even running at 1080p, it would not sync properly.
Multi-channel audio is possible. But ultimately I realized that only 2 of my 6 TVs can do anything with it, and even then it is only really for certain content. So I abandoned the experiments, and just use different source when necessary.
Don't know about CC. Not even sure how it is encoded. But wondering if the local box could do that with a little AI help.
Not sure why the encoder vendors don't tackle both. But perhaps it allows them to fly under the radar of the content owners.
