Add a playlist/subscribe feature for things like the MCU that have many titles being released that should be watched in a certain order.
It would be nice if you could choose to have new titles from the MCU automatically added to your watchlist. Also if you could view a calendar specifically of that universe to make sure you are watching in the right order. For example, the DC superhero shows from the CW overlap episode by episode instead of season by season, which can be a nightmare to manage. Or another example would be Star Wars Clone Wars which inexplicably released episodes out of order, but someone in the Simkl community could create a playlist that has the shows in the right order.