I also have a B&M deep trans pan installed, and I check trans fluid weekly.
It does not happen quickly though. I need to drive up hill in a stop&go traffic for roughly 30 mins for the temperature to reach 200 degrees. It does not go higher though. If the traffic starts moving, the temperature drops to 180.
I verified the #s with a scanner and it shows the same things.
I think the key here is "STOP&GO". Since I don't move more than several feet at a time, there's no airflow through the radiators, hence the temperature is rising. When eFans kick in even at lower speed or the traffic starts moving, the air flow is enough to cool everything down.
Ah, when