Build your own app. 
Selecting the Roon Zone generates a FLAC radio stream that autoplays on the selected zone in Roon – no further action required (communication via a small extension). Fixed clock @ 96 kHz plays uninterrupted – auto clock follows the correct sample rate, but leaves a small gap at rate changes as it needs to tear down/restart the stream. Best I can do with Roon ATM.
Small peek at Basso: a nice little Apple Music player (macOS, iOS, iPadOS, tvOS, watchOS – for me only, so far ;-)), playing Apple Music bit-perfect to cloud controlled zones (a la Connect): anything Apple, Sonos (via official Control API), UPnP (HQ Player, KEF LS60, Meridian Ellipse & Naim Mu-so) and Roon (via radio).
