[Big-Foot]

Marc / All - Whenever you take your car out on the track and REALLY USE your brakes (regardless of your choice of brake calipers/rotors/fluid) - you should always bleed your brakes before the next time you hit the track.
When you put a lot of heat into your brake fluid, you lower it's boiling point each successive time out. You need to get the fluid that is currently in your caliper's bled out and replaced. That's not to say that you need a total changing of the fluid from the master cylinders all the way to the bleeder valves on the calipers - just that fluid that is in the calipers itself.
The rule of thumb I've used for years quite successfully is at least 4 full strokes of the brake pedal per axle if I did not experience much if any fading. 6 full strokes if I did have fading.

Running fresh air ducts to the insides of your rotors will generally reduce the need to do 6 pump bleed sessions a lot but does not negate the requirement to bleed the brakes.

Note - When you have experienced brake fade due to boiling fluid, you will usually notice that your brake pedal is much more firm once it has cooled down. This is what gives so many people a false sense of security about their brakes. You have reduced your 600f brake fluid to something close to half it's original temperature tolerance.

Marc - also to your particular brakes - Having also used the Vette PBR Calipers not only in Corvettes but in SCCA American Sedan cars, I found these calipers to "Splay" causing a very un-even contact with the rotor and very poor wear charateristics on the pads. We tried everything to make these calipers stronger so they would not splay out but where unsuccessful. Since it was the outboard pad that would not contact well, we were putting much more heat into the inner pad. One thing that I tried (and it worked quite well) was to put a thin bead of Hi-Temp RTV around the part of the pad that contacts the caliper's piston. Let it skin-up for about 30 minutes and then install the pad, bleed caliper and seat the pad pretty quickly. The (now very thin) layer of RTV between the piston and the pad's backing plate was a very good insulator that would transmit MUCH less heat into the piston and fluid.