Interesting oven. Is there a deflector plate above the flame?
I do not use a steel plate, but my understanding is that steel
cooks the bottom faster, which is ok BUT you have to have a top heat source, ie broiler, to blast the top side just before the bottom is done.
An IR therm would answer some questions here. Obviously with a 7-8 min bake and the top getting color you have enough heat in the air. Screens are REALLY cheap, on the web around $4. However if there is no deflector plate above the flame you might want to move the screen to the very top of the oven.