When I close Spotify using either the Quit menu option or the X to close the application, it saves my play queue state (and my current point in the song I’m listening to). However, when I reboot my system, Spotify doesn’t do this. (This suggests to me that the snap isn’t getting the chance to gracefully quit.)
Given that basically the only time I restart Spotify is when I restart my machine, I’m getting pretty sick of the song I happened to be listening to last time I did close Spotify gracefully. 
Can we do something about this?