You're not. Not if you heat your water before putting in the grounds. Practically speaking, once you heat your water, it's a matter of seconds to get the coffee rolling.
You should try it.
You should try it.
With water at 4C, puts the most water inside the pressure chamber, leading to the greatest pressure change for a given delta(T). Instead, if the water is just below boiling, the water going through the grinds must be higher than 100 C (since the pressure raises the boiling point).
It'll brew faster, and there is an argument to be made that quicker brews lead to less burning. But the T would be highest.
Boiling less quickly (i.e. using lower heat) might put the coffee in contact with boiling water for longer. So it would seem high heat and cold water would be the way to go if you want to minimize the temperature-time product of the beans-to-water contact.