New Back Armor Slot and Balanced Transportation

I feel like with the problems that the bundles have posed that it might just be easier to use a backpack, now I do not know the developer's stance on it, but my idea is this, They need to add a back slot to the game, in this back slot they could have many items that could be put there such as an elytra or backpack. This could work with a Chestplate making it better protection, the only catch that would make this balanced and all, is you can only fly with the elytra for 30 seconds before it has to recharge, and to balance the backpack and make it less like a shulker, you can only hold items in it while it's on your back. You could also add many other items such as the quiver to add more arrow storage and maybe an air tank that improves underwater breathing, maybe even a portable furnace. All of these things only working whilst on the back, making it a trade off for using any one of them and making it suitable for any playstyle. With the coming updates, new things could be added for it, I feel like this would fit nicely inside of the combat revamp where I hope the fletching table gets a use, make you need it to craft a quiver or special new arrows. The new items could also balance transportation, making building infrastructure more rewarding instead of after getting an elytra not using ice boats or railways or horses.