@andrewilley I know the setting, but there are likely some users that want duplicates for their playlists.
Also is it not possible for the app to recognize when a single file is being added to a playlist rather than multiple? Because the indicators would make the most sense for adding individual tracks.
That's where I think the Don't Add Duplicates setting would really shine, too, is when adding multiple tracks to a playlist because the indicators wouldn't work under that context.