Horse Inventory and Quick Use?

[Zourin]

I think some of the menus oversell some of the things you can do in the game, unless someone can point out what I'm missing.

 

- In the game controls screen, it says that tapping right on the D-pad is for "quick use item".  How the hell do you use this? There's no option anywhere to set a 'quick use' item, and tapping it does nothing.

 

- In the Help menu, it says you can store Provisions in your horses' inventory when your satchel gets full. There is no option to move anything anywhere in the interface except "discard".