@JuiceWSA I saw the "work-around" first time through and haven't implemented it because it's not a really a work around at all. It's a way of shoehorning the content in so it simply exists from within Plex, losing all semblance of organization or identifying features.
I came up with my own solution, which is only slightly better (imo)...
I moved the extra content into a new show folder with an altered name, sorted and named the content relative to the new show folder, manually added images and meta data after scanning, and finally edited the sort name to that they were listed alongside the show they belonged to. Sample file structure below...
Futurama - s00e01 - Christmas Special.mkv
Futurama - s01e01.mkv
Futurama - s01e02.mkv
Season ## [etc...]
EXTRAS: Futurama - s01e01 - Deleted Scenes from Season 1.mkv
EXTRAS: Futurama - s02e01 - Featurette.avi
Season ## [etc...]
A couple problems right away from this approach:
1) Plex is still trying to match the show to TVDB content, so if "Futurama Extras" matches too closely to the real show title "Futurama" then Plex will try and merge the extras content back into the original show anyway (and just create a bunch of dupe entries). So the fake show name needs to be different enough that Plex cannot identify it (Using something that changes the beginning of the name seems to work best).
2) Extras content is removed from the original show that it belongs to. So while you do gain a little bit of organization at the season level, you lose a little bit at the show level. Also, using a fake name with a different first letter than the original means the shows won't appear next to each other, but this can be fixed by editing the "sort name" back to the original.
3) You lose show metadata and have to manually add it for the "fake" instance.
My opinion is that having the season-level organization is a bit more important and useful than keeping them contained in the same show (of course having both would be far better, if the devs would actually fix this (FYI this is broken behavior)... but anyway...). Using the other "work-around" still doesn't get you show-names or episode-level meta so the loss of meta is relatively the same with either method.