Hey Carl. For me, oiling the rim pre bake helps with browning and helps make the rim crispy which we like. Side effects seem to be an increase in leoparding and blistering, which we also like. I got the idea from a Tom Lehman video and I know that Pizzeria Mozza does it as well. As far as oven spring, I'm not so sure. Over in the "more flavor in the dough" thread, in the New York forum, I posted a pic of a pie with one section oiled and one not. The difference in browning was pretty obvious and the oiled section had a bit better spring but that may have just been a coincidence.