that's a good set-up you've got, the steel gives you a lot of heat overhead to cook the top, and your pie isn't on the steel long enough to burn. I'm like you, I don't like running the broiler, and the steel has a tendency to burn the botton crust if the whole bake is completed on it. I would max out my temp., if your oven will go to 550, that's where I'd be.
Thanks DMC, I'm making the steel work for me instead of the opposite.
In my 2 attempts at 550, the bottom cooks so fast (probably around 1.5 minutes before significant charring begins) that the pizza isn't really strong enough to move it yet. Additionally, the bottom still cooks when its on the grill racks so if your bottom is done after its time on the steel, it will be over-done after 5 more minutes on the grill sheets. Know what I'm saying?
Although I'm still new at this method, I'm learning there is a very small window of too much & too little heat. I believe 525 may be the magic number, which will be my next test. These are some of my preliminary findings:
@550: Bottom starts to char after 1.5 minutes, after moved down the top is done after 5-6 additional minutes - Total time = 5.5-6.5 minutes
@500: Bottom starts to char after 3 minutes, after moved down the top is done after 6-7 additional minutes - Total time = 9-10 minutes
I'm hoping @525 I'll be somewhere around 2-2.5 on the bottom & 5.5-6.5 on top which = 7.5-9 minutes total. I think 2 minutes may be the minimum time where it becomes safe to move such a big pizza. I'm also only using a wood peel so that probably has a lot to do with it.
If anyone is still awake, thanks for looking. Hard to believe but this is quite fun for me.