The embedded sdk is a dumbed down library providing playback, control is performed using Spotify's apps (via Spotify Connect). Libspotify provides playback and

The embedded sdk is a dumbed down library providing playback, control is performed using Spotify's apps (via Spotify Connect). Libspotify provides playback and control i.e. everything needed to implement your own version of Spotify's app (but it predates Spotify Connect so has zero support for it). It's not much of a replacement. And as you say, there is no public access anyway.