Omid, thank you for the reply. I can see what you mean in the third picture. Maybe the ash that is against the retainer insulates the steel which would greatly reduce the temps radiating from it.
...does that effect happen to the cornicione every time you use the steel? I am away from home until next week, and I can't wait to experiment with some ideas.
You are welcome. The effect does not happen every time I use the steel guard. I believe it primarily depends on how low or high the coals (supporting the burning logs) are stacked up and how far from the steel guard my pizzas are positioned. I would posit that the floor temperature and intensity of flames are also important factors to consider. It is such a dynamic environment inside the oven at high temperatures. Good day!