Mike--
Jon is swift, but he did pass a protest tear-down recently. Remember, he weighs about 125 lbs. wringing wet. He really did come out of nowhere, I met him about 18 months ago at a DE when he brought his 996 -- he had just gotten his 944 and was prepping it for racing. Looks like he's a pretty quick study!
Maybe its just as well that he won't be there, there won't be all that pressure to go too fast. One thing to consider is that Jon uses 15 inch rims and thus a smaller rolling diameter for an effective lower gearing and better acceleration. I'm thinking of trying some 15's for comparison.
Rick