A trial Roon User for about three days, myself, but quite keen on better using Chromecast audio.
My initial experiments using Chromecast Audio as an endpoint on a RoonServer running on Windows 10 i7 PC:
1) Have installed VBCable base on Server and Audio-cast. Output from Chromecast Audio via Toslink is input to a "legacy" Young Dac optical input ==>> Preamp, etc.
The Device is VB-Audio Virtual Cable (WASAPI) .
I have been using this set-up all day yesterday and today, casting from an Apple Ipad and from two legacy android Tablets.
I have found the set-up quite stable and the results are quite bewildering given the low price of Chromecast audio. I have played 96K and 192K. It will be nice when we will be able to use Chromecast audio without installing additional drivers or programs like the two above mentioned.
Pls. note that PC Server is connnected to Ethernet and Chromecast Audio is connected to USB 4ports (Sitecom) Hub from which it draws its power. A Sitecom Ethernet to USB dongle is also connected to the USB Hub. The Ehernet network connection is quite stable. I had been trying to use Chromecasts without WIFI (!). The experimentation has been worthwhile.
Using Chromecast Audio on the Macs, outside of Google products, has been a bit frustrating.