I have a playlist that contains above 1000 songs. It's SO big and I remember the order of the songs based on the date of addition and occasionally would like to know where the song is in the list. implement a green dot on the scrollbar Which represents the song you are currently listening to would be a very useful thing on very very large playlists. so you would know each time the location in the mass of the song in play at that time.
This idea can be extended through all the type of list of song, and so, to all Spotify.
This feature might be possible to be or not to be abled in settings.
And after all, an extra point in the scrollbar doesn't costs nothing to anyone :)