Congratulations, Britt, you are one of an extremely small group of people lucky enough to have an oven that runs hot enough for 4 minute bakes on a regular baking stone. 630 is definitely not something you see much in an unmodified oven and, at the temp, you don't need steel plate.
Did the company cramp your style? You had a little more bowling (thin towards the center) than on your previous pies.
Now that you've got your oven setup in order, I think your ready for better flour. Where abouts are you located?