Just an update: I'm at a place where I'm getting much happier with my Sicilian style. I did the three stage bake again (parbake no toppings, parbake toppings, broiler with some more mozz,) but I changed the baking times. I did, about, 5 in the first stage as opposed to my first 4 minutes, about 4 to 4:30 in the second stage as opposed to my first three minutes, and about 3 minutes under the broiler (but a lot of turning) as opposed to one minute.
So, about 9 to 9:30 this time as opposed to 7 minutes last time for the total bake, plus some work under the broiler. The bottom was a gorgeous golden brown and I was very happy with it. Only thing was I used KA bread flour this time so it was slightly chewier, and I lowered the hydration by 5% to 65% so I think next time I'll use All Purpose and 70% hydration and it will be perfect!