The PlexAPI supports adding items to the users watchlist, which is already accessible by the fact that a server connecting with the users credentials needs to be created in the first place. The items missing from a collection also already include the necessary data that would be used as the input for this function, as those are necessary to be able for the data to be passed to Radarr/Sonarr. This way, plexdebrid and its variations can be used to then easily gather that content.

The current system does not allow collections of media to be easily added to a watchlist, while connecting this to the current system detecting missing content would allow content of any size to easily be added to plex. With a possible use case being the most popular content on streaming services, or essentially any list of content able to be processed by Kometa.

This seems to be a relatively small change, i just don't know how i would be able to call this function correctly.