I tested on Unraid today, Docker to Docker. The only issue I encountered really wasn't an issue, but a small oversight. Due to the way Docker works with the TCP stack you can't run Emby using the "bridge" method, which uses the NAS's IP, and connect to C-DVR running in another Docker. It needs to have its own IP or it won't be able to connect to C-DVR, which already had its own IP. Once I fixed that my one test channel worked beautifully.
Now it's time to scrub the M3U files, tighten up the channel numbers, and go live. Thanks again to those that provided the information!