Why do we turn down the oven after introducing the bread?
It's commonplace to recommend turning down the temperature from 500 to 450 when the proofed loaf is put in the oven. Why do we do that? In a WFO, you don't do that, and I would expect that in a commercial deck oven you wouldn't either. Is it to simulate a stone hearth which might be hotter than the air in the oven? I don't think so.
I think turning the heat down is to prevent the top element from coming on when the door is opened, ice cubes inserted, and a few pounds of room temperature dough added. The stone adds thermal mass, but the oven thermostat isn't sensing the stone (which is probably masked from the sensor by the bread anyway), so the heating elements turn on at full blast to correct the temperature, and the top of the bread gets a lot hotter than 500 due to the red-hot element just inches away from it. Turning the temperature down is exactly the same as turning off the oven for a period of time, till the oven has reached equilibrium at the new set point. The bread bakes from the retained heat of the oven in that critical first minutes in the oven.
That is one reason that the cloche, the no-knead casserole, and Susan's pyrex bowl produce such good bread. No burning. The other (and probably the main) reason is that they trap the humidity of the bread as it heats and keep the outer layer of the bread gelatinized and prevent the slashes from hardening too soon. Without the cover, you need to turn the oven off for a bit to prevent burning.
Ovens have different cooling rates, just as they have different heating rates. My present oven is very well insulated, and I'm certain that old ovens cool off pretty quickly, so they would cook at a lower temperature than mine. I think more consistent results would be obtained by using a cover for the first part of the bake, and just baking at the desired temperature.