I painted my rocker cover with VHT base, colour and lacquer, only thing I found was it went on so thick that the bolts caused some cracking when held down.
As for using the VHT base and lacquer, why not just shell out for some of the proper paint? They aren't going to act as an insulator by any means. I've known people to use Hammerite on their brakes and it bubbles when hot, when it cools down it goes back to normal. But that should only happen between 150 and 200 Celsius.... As for it only generating that much heat on a track, an emergency stop will heat them up a lot, and if its not the right paint, the constant heating and cooling will do you no favours. I'd do it properly.