I have only one frozen pizza and two pizza boxes, personally I prefer to use the pizza boxes first because I have the possibility that another piece will arrive by chance to recharge them, so I put the frozen pizza in reserve, until it reaches a point where nothing falls and that's when I use it.
With the utility it has, I plan to gather to buy one more piece of frozen pizza in the next round, because it would help me to do more missions per day without depending on luck so that a piece falls in one of the boxes, which can not happen, because everything is a matter of chance.