I didn't have heat indicating paint on the rotors, and don't have a IR pyrometer, so I don't know the temps got to...this was mostly a motor break-in session.
The places I was having the most problem with the rears was turn 3 (hard braking area after a very long straight), turn 7 into the safety pin (hard braking after long straight), turn 10 (hard braking after straight). Now that I think about it, is there a such thing as easy braking on a race track?
Maybe next time, I'll close up the ducts a little.

My brake adjuster is of the pressure limiting type, so yes, the rear brakes were limited to their max.

I guess changing to larger ABS calipers up front and not changing the size of the rear calipers causes the rears to have too much pressure. I didn't have the issue with non-ABS brakes.