I stream 4k hdr10 10bit videos just fine (with transcoding) Enjoy my modified profile.
Replace the original chromecast.xml with this and restart the Plex service.
This is a really janky profle I put together. You can ignore part of the commentary I added. It’s so I can modify the file on my phone and then ssh it to my server easily enough.
this is still a work in progress, but i’ve made some decent progress. I use Tautulli to monitor the actual streams too. very helpful!
I have since made some changes to my Plex Chromecast.xml profile. as the vizio M series has a rather wide array of supported formats. I’m able to directly stream 4k media and DTS audio to my TV. Atmos is converted to Vorbis but seems to maintain the 7.1 channels.
Anyway, I hope it helps you on your journey.
Oh, and I cast. I use the app on my phone or mini tablet that came with my M series. It doesn’t play through the phone obviously…the phone just acts as a remote.