ALEXA > SONOS > Plex....
I've asked in the plex forum and was told
Per that list of supported companion “receiver” applications, It’s likely that you are not able to tell other Plex controller applications to playback music on the Sonos. Sonos isn’t listed as a receiver capable application.
So, my question ultimately is will it work.
Seems no here because of a Sonon deficiency.
Should Alexa voice commands to tell Plex to play something to my Sonos speaker work?