The feature I'd like to suggest is to port this behaviour in the game, by making the PC working like an Ender Chest : when using it normally, it just opens the Pokemon Storage System ; when sneak + using, it opens a (simple or even double chest ?) item storage, shared among all PCs by the player. I think it might be a great feature because it would add some nice utility to the PC without beaing game-breaker (we already have Ender Chests and Shulker Boxes)
Extra suggestion, while talking about the PC : being able to manage equipped items while in Pokemon Storage System