Apologies if I missed it but couldn't see where you said your were after 5.1.2 or 7.1.2 (I do see someone asked the question).
You're correct though I'm so far as the cinema 70 will be limited to 7.1/5.1.2. It does have pre-outs for all channels though.
I have the same issue with tidal connect and my Chromecast. Going to experiment with USB Audio Player Pro as a remote and Chromecast as renderer I think.
If you've already got a Dac which has USB in and have an old android phone knocking about then USB audio pro and a OTG cable is all you need. You need spend no more than £15 for a perfectly easy to use streamer with a a screen.