i believe it would be interesting to be able to put these items in the Item Display:

Golden Enchanted Apple, Totem of Undying, Nether Star and Heart of the Sea

i think it is cooler than simply putting it in an Item Frame

Hey! Thanks for the suggestion, I'd love to add these items someday :D
I definitely will make a model for Heart of the Sea. Enchanted Golden Apple is also an interesting thing, but I'm not sure it's possible to add enchanted glint to it. As for the Nether Star... I'll have to do something special for it!