I would appreciate if spotify could inform me that other versions of a certain song are already in my selection.
Eg. If I have remastered version of Kashmir by Led Zeppelin in my selection, there is no notification that would inform me that I don't have to add original version (as can be seen in the attachments). If I forget about adding the remaster, I can accidentaly add the same song twice (or even multiple times). This also applies for song or album re-issues, compilations, live versions etc.
The solution seems simple enough. Just add a new tiny column that would inform me that I have a version of certain song already in my selection. The symbol could be exclamation mark, or it could be colour based, or whatever and upon hovering the mouse over or clicking on it would display the version(s) of the song in your selection.
I bodged together a possible way how this could look like. The first two images are of Led Zeppelin. Bc I'm a fan I have most of their songs in my selection, though not the most popular versions, so in this case there would be a lot of exclamation marks and it would look like this:
Next I have chosen a more common situation. With The Supremes I like just one different version of a song than the most popular one. So in most situations this feature could look something like this:
Please do upvote this even if you don't like this particular graphical design, but you support the general idea! ... The aforementioned design is just a suggestion not a necessity and should this idea get into Spotify, they would obviously have graphic designers to find the best solution.