I had raised the question about support for more modern Samba support on Sonos.

I was greeted with the lovely respones that it is “on its way”. 

Forgive me if I don’t hold my breath.

Fortunately, if you have an open source version of Samba 4 (such as I do through my OpenWRT router), it now supports legacy (insecure) connections and allows Sonos to connect.

Well done in relying on others to provide compatibility, Sonos, even if you refuse to do anything. I hope a similar tactic works for you in suing Google for copying your network music synchronisation. I hope you get your reward frow them, but I don’t rely on you to put the proceeds to fixing your issues or inventing your way forwards...