There was a 4k set of both extended and theatrical editions of LotR and Hobbit that had a unique new exclusive bonus features disc included (which was a video of the premiere of the first movie plus reunions hosted by Stephen Colbert). Its 31 discs cause they include both 4k and Bd versions of the new 4k master for both cuts of each film. If you want to fall down a rabbit hole of LotR special features. The theatrical editions actually have different special features plus there is some random miscellanous stuff they have done too like some National Geographic DVDs.
Picked up a few of the same stuff you did. Still jealous of Black and Black RX as a Canadian. But was able to get Loki for $50 CAD at walmart. (Blu Ray version) Also I might have to start cutting or folding the j-cards that come with a lot of steelbooks to have them in the case as I still have no idea what to do with them