I read it as saying you don't need 500C if you have a pizza stone or cast iron pan for transferring heat fast. So use a object that has a significant heat capac

I read it as saying you don't need 500C if you have a pizza stone or cast iron pan for transferring heat fast. So use a object that has a significant heat capacity to buffer heat, and you don't need the oven to be as hot. (Stone has higher heat capacity per unit mass than iron, but large cast iron pans are heavier than typical pizza stones, so the two objects probably have similar heat capacities.)