Pete dumps the oil after every track day, so I don't think the oil has time to break down and sludge. Helps when you have a trailer so you don't have to worry about driving it home .
At the last track day, using Penrite Racing 10W-40, I was regularly hitting 130°C lol. Car still drove home fine, dumped the oil after as I didn't want to risk it. Oil was about 3,000 km when I hit the track lol.