Expandable inventory to show armor and offhand while in chests

When you are interacting with a crafting table, furnace, chest, horse or llama inventory, etc., you should still be able to see your player's armor slots and offhand. This would make putting items directly into chests much easier. And with the exception of the crafting table UI, the 2x2 regular crafting slot that is always available to the character should always be present as well. We shouldn't have to go back and forth from our regular inventory to the chest or furnace or horse or whatever is being interacted with, just to take something out of our left hand or a helmet off our head.

To clarify I'm NOT asking for backpacks here. I'm saying we should be able to see armor, offhand, and possibly 2x2 crafting in all the UI's like chests and horses where it is missing. This would make logistics of organizing items so much easier.