To my knowledge with patents you can use one if you can get your hands on one. You can even use one if you make your own. You are just unable to sell them, that is more where they get you. Besides if you make your own from the concept but make certain changes you are allowed to sell them if you really feel the need.
This might be useful to get a nice layer of cheese to start with but I personally would fill in certain areas to make a more tasty and appealing pizza. I could see how this would save pie making time, they have a catch tray under the thing. So any lost cheese can be recovered.