Do I understand correctly that Plex Sonic Analysis only analyses tracks in your local library AND then only identifies sonic matches across tracks in your local library?
Just spent some time with it, expecting it to be a dream-come-true discovery method in combo with Tidal… only to be sorely disappointed. 
Unless I misunderstood the feature completely, it seems useful mainly to those who:
- Love automatic playlists or other kind of “focused radio” playback
- Do not know their own library by heart (too many tracks / albums / artists)
- Do not have their own library sonically interlinked (e.g. by customized genres or tags)
… I unfortunately do not fall into any of the above categories. But maybe I am still missing something important here? Many people seem hyping the Sonic feature…
NOTE: The TOUCHDOWN promo code for 1-month free Plex Pass still seem to work.