Hey. First off, love Deezer. Great app.
I'm someone who values playlist organisation over everything. I make tons of playlists to organize my music from many genres. Currently when adding a track to a playlist, there's no way to tell it's already in a playlist without opening it or trying to add to it. It would be great if Deezer could scan playlists for that track and have it mark every playlist which already contains said track. I've made an example of my idea below. Feel free to copy it.
That’s true, it has been discussed too long, but now they have a lot of work.