It was a bit dense for me in parts, but isn't it a very standard bread cooking trick to stick a cast iron pan in the oven to give it more thermal mass?
I'm also quite curious about these cooking temperatures, I know I'm never going to hit those in my electric stove, and I do cook deep dish pizzas longer at a lower temperature so they aren't goopy dough on the bottom. I wish I could try cooking them hotter, they still come out like crackers at 475F sometimes.
I'm curious, regarding your note about pizza stone temperature, do you make the pizza dough stretched and topped and then... put it on the already hot stone? How do you get the dough from the place you topped it to the stone without it falling to pieces?
What kind of stone could it be that a cast iron pan wouldn't be both higher thermal conductivity and also higher heat capacity? Are you using temperatures too high for cast iron?