As I am getting older, this is getting hard for me as well, but, Your understanding is correct.
The MAT reading depends on a few factors; Ambient, Amount of alky, Boost, Location of MAT, Type of alky, Injection point of the alky, Turbo efficiency, Engine temp, etc.
FWIW, I have seen closer to 140-150F at 19PSI on a 95F track day.
Hope this helps.