There is already a way to trigger relevant action for an item, e.g. eat food, drink a potion, use bandage, zap a wand. The list might extend in future to 'equip' which would make this feature even more useful. Just allow instantly picking an item and invoking that action by a single keypress. Make sure to keep preferences if item is lost and regained again or if it's status is changed, e.g. identified or rotten (so that if I quickmarked iron ration ate it and got a new one I don't have to re-quickmark it again).

Might be a candidate for ease of use?