I have found a draft door to be critical in maintaining a well-burning fire. Use it during the fire-up stage to keep a steady stream of fast air moving in and smoke from flowing out. Between pizzas, or after adding wood, put it on for additional "turbocharging" of the airflow. It also helps to keep heat in the oven.
A draft door is a door that stands on stilts about 2-3" above the floor of the oven. It can also be made with a crescent-shaped opening in the bottom. It channels a rapid stream of air to the fire in the chamber. I don't know to what extent it may cool off the floor, but it does channel the smoke away from the top of the arch and up the vent.