[venusenvy47]

I'm not clear on the question being asked. I currently am signed in with my Spotify account on Alexa, my phone and my tablet. I can stream the same music from all four Alexa devices in the house, and also concurrently on my phone and tablet. I don't normally want all these devices playing (at home I just need the Alexa devices to be playing), and I actually have more issues where music is playing from more devices than I want.

My Alexa devices are scattered about the house, so I'm not interested in stereo separation in a single room - maybe they are talking about the timing required for that.