Okay, I'm getting really good at this, and I have to make some notes on what I've been doing: 425 degrees on the stone for 6.5 minutes. Instant polenta underneath for motion... You need some corn meal to slide the pizza off the peel, and onto the pre-heated stone on the grill. I've used stone-ground coarse corn meal, and it's like eating a pizza that's been dropped onto gravel. The instant polenta still has the ball-bearing effect, doesn't burn (like breadcrumb does), and isn't crunchy.
I used Trader Joe's whole-wheat pizza dough. I keep a bunch in the freezer and thaw them on the counter in the bag. The dough ball HAS to be room temperature, and if it is wet and tacky, it has to be well-floured all around before stretching. Then the peel has to be floured, and then a light coating of corn meal spread on. I build the pizza right on the peel. Don't wait too long - it will begin to stick, so get it on the grill.
This temperature is perfect. The dough will cook and rise before the bottom blackens. I check it at about 6 minutes. My grill has a thermometer on the hood. Not as hot: dough doesn't cook. Too hot: blackened crust.
This pizza is topped with mushroom sauce, and leftover sauteed spinach that I had cooked with garlic and onions. The cheese is a shredded mix, with parmesan and Italian herb seasoning added (gives it that pizza flavor). Lastly, I added basil from the garden after cooking.