How to bake multiple mini pizzas at the same time?

I'm trying to bake around 12 - 24 mini pizzas at the same time.  This means that I need to put them all in and pull them all out at the same time.  Meaning they can't be baked on a stone or steel as you can't pull those out of the oven (they retain heat and will be too hot to remove).

I've tried baking them on cookie sheets, but since the tray itself is not preheated, the bottoms don't cook enough.  How do you bake multiple pizza bites at the same time?  Right now I end up baking them on the steel but only 4 at a time so I can manage putting them in an pulling them out without releasing too much heat from the oven and without burning.  But I would like to save time and make more at a time.  Any ideas?