I work in the classic Italian car world, so am aware of all the tricks used by people to get parts used, and the taking the scruitineers around various small garages and out to lunch whilst identification plates are changed whilst people are not looking.
However to finish first, first you have to finish.
On any race car, controlling underbonnet temperatures well allows you to make and retain peak power and reliability for as long as possible. Looking at the car its probably gives an increase in stability at speed.