if its double stack, i would use say top one for plain cheese or 1 topping pizzas - in this case you want to direct more heat from the bottom into the pan - so have more fingers with openings on bottom and you can even speed up this belt, so here pizza will cook faster and more on bottom and not burning top at the same time (i like my cheese pizza almost white = without burn cheese at least and that will happen if you put too much heat on top. now the bottom oven will be for few toppings and specialty (loaded) pizzas - here you will distribute heat evenly between finger directions (top and bottom) and decriese the belt speed lightly, so that pizza crust is nice and all the toppings are cooked thru.
