Would love to be able to add and remove shows manually from On Deck (without messing with the Watched/Unwatched settings). It's great that Plex decides what's included for us, but customization of the section would make it even better.
I too would like some more granular control of the on deck feature. I dislike that plex suggests I watch the cartoons my kids accounts are watching, even though my user has the entire series unwatched.
