I have numerous streams set up as URLs via the "My Radio Stations" functionality in my Sonos Arc. 

Included among these are Soma.FM's Groove Salad (and a number of Soma’s other streams), and a bunch of subscription-only streams from DI.FM.

I can easily start these from the Sonos controllers on my Mac, iPhone, and iPad.

How do I start these streams with Sonos Voice Control? I've tried a bunch of different ways of phrasing the request, and SVC doesn't seem to understand.

I'm not looking for any level of interaction with these services (or the others that I use by URL) - I do NOT care about Next/Previous, Forward/Rewind, Shuffle, Repeat (none of these are available with a URL-based stream anyway) - I just want SVC to start playing the requested URL-based streams that are already saved in "My Radio Stations".

(It would be nice if the "what's playing" request worked - the controller apps seem to be able to pull this from the mp3/aac stream just fine - but I'd give even that up if I could just ask SVC to stream the station.)

So, what is the SVC solution for playing streams from "My Radio Stations"?

...

/ And, because someone may suggest it, yes, I know that I can ask Sonos to play "Groove Salad", and get that one fed through from TuneIn (that is, the TuneIn service itself, not the URLs that Sonos is apparently storing in TuneIn).

This involves first listening to a TuneIn jingle and an obnoxious commercial at the front of the stream - every single time (literally, I tried starting/stopping 3 times within a couple of minutes, and got the commercial every time - I heard more jingle/commercial than actual music). No thanks - first off, the jingle/commercial, as noted, is annoying, second, Groove Salad is a free service, and, third, I already contribute to them regularly to help keep them on the air - I won't support TuneIn feeding vampirishly off of that.

And, of course, TuneIn's radio service cannot provide my subscriber-only streams from DI.FM - those have to be URL-based and can’t be shared. ]