I will look into the Spotify Issues with Arylic.
I am committed to implementing Multiroom in our Villa in Spain-Multiroom Spain. It would be nice to offer our guests a unilateral solution based on the Music Subscription they have (e.g. Spotify, Amazon, Deezer). For this reason I am interested and committed to finding cool solutions for them to enjoy 
From a personal point of view I have a large digital music collection which is sitting on a Synology NAS (there is a Music Server which syncronises between UK & Spain). The 24bit/96kHz tracks sound amazing but again that is down to the fact that the original recordings are good.
So my major efforts on Voice Control will be playing playlists from this Server and Creating Multiroom Zones using Home Assistant which can then be exposed to Google Assistant, Alexa and possibly my next generation of Voice Control with Open Source Software. The experience is totally transferrable to other platforms as in simplistic terms Music Streaming consists of a Source, Sink/Target and Control Point. The rest is just communications hurdles that prevent the perfect triangle
I think Linkplay in HA will really help the Zone Control side of things.
Regards, Kevin