What is the pyrometer used for?

[JMBT]

It’s good for making sure you aren’t cooking everything, like the turbo, manifold, head,…etc., with too much heat when you are working the motor hard.

Also, knowing when to downshift on a hill, (even if the motor sounds good and is pulling fine in the proper rpm range, sometimes dropping a gear will bring the exhaust temp down by making the work load on the engine less)

Add in what you said about cooling off before shut down and it makes it a very useful tool for increasing the longevity of the motor!