Mark, I think you'll be pleased with the results. For every dough and oven setup there's going to be an ideal broiling start point, so you might get better results a little earlier, but I think the generally concept of initial bottom heat to send the crust soaring/billowing and then later top heat to set it and brown it is sound. I have no doubt that there will be an ideal window to apply the top heat so that the spring is at it's peak- too early and the dough will not have risen enough, too late and the dough might possibly collapse.
At some point I want to connect a webcam to my oven door so I can approach this a little more scientifically. Until then, though, I'm very confident that late broiling is the way to go.
Interesting information you've got here. I have a feeling you can take most of the guessing out of when to broil by baking your pizza the way we do commercially....that is, bake from the bottom up. Constantly monitor the bottom of your pizza, and based on how long your particular oven browns the top on broil, use this info to figure when to turn on the broiler. I'm guessing one could figure out when he had a minute or minute and a half to go on the bottom, then turn on the broiler....and if by chance the broiler isn't working fast enough, simply throw a screen under your pizza to stop the bottom form browning further. Very, very interesting stuff Scott.