New Inventory slot for chestplates

Mojang said no to armor+Elytra. But here I have an idea that may satisfy everyone. There would be a new slot for the chestplate, where we can put Chestplates, Elytras, Backpacks/Shulker boxes and Banners. However, if we put a Chestplate on our main armor slot, and an Elytra/Backpack/Shulker box, we will show the Elytra/Backpack/Shulker box on our back, but it would be like it wasn't there, and we can't use the Elytra or access extra inventory space. The same will work if we put the Chestplate there: it will be shown, but only for the look, because we won't have the armor points. With Banners, instead, if we put them, we will show them on our back, like Raid Captains do with the Ominous Banner. A cool addition that can satisfy everyone.