My OCD loves to sort my inventory manually. I put food and resources at the bottom right, my weapons and such in the top left, and resources I pick up, just fill in the rest.
I'd love the ability to "Lock" the position of items within my inventory, that way I can still use the "Sort" function but it won't move those items.
It would be extra beneficial if it could "remember" those locations when I die and go back and pick my backpack up.