I doubt the NSX was a one-use engine, if it was it wasn't near far enough ahead of the AMS car in terms of top end speed for that. (AMS car was missing 5th gear and may have had a head gasket issue) In full form the AMS car is probably right with or ahead of the NSX.
Sometimes I think that Rado has one-use engines though - I haven't been to a weekend where they have left the same engine in the Scion the whole time yet.
As far as staying left at the kink, it depends on the car.. some setups get away with it, some don't. It does cost you runout, but in the right car it's still easy. I was actually surprised at some of the low-speed data coming from people this past weekend in the kink.. Daddio's kink low-speed seems to be less in the AMS car than it is in a stock Evo. (both on GPS) Go figure..