The guard device is limited because of the fact that not every item can be used by it. This also causes issues like the creative inventory being split because of the guard tag.
So I propose that the guard device should be changed in a way so that it doesn’t limit what the creator can use with it and that it doesn’t cause outside issues like with the inventory sorting. The way that I think it could be done the best would be to either make how guards work similar to the npc device where it can use any item and can hold multiple items. And with that change, the guard tag should be removed so that sorting will be fixed in the creative inventory.