Chris, I took note of the fans switching on and off todayPersonally, I like a coolant temp of 187 to 192 F. This will have a center, or hair right of center gauge reading.
Front fan is 80/88 deg C
Puller fan is 91/99 deg C
The fans are alternating between 88 and 91 deg C (190 to 195 deg F) in normal operation.
In very heavy traffic (before the vents) and on extended idling the fan would trigger very rarely (99 deg C)
I got a surprise today, turning off the engine and parking the 540 after 15 mins the front fan didn't switch on for a minute (it triggers at 80 deg C / 176 deg F) so the vents are very good at letting heat out from the engine bay
I'll see how the temps behave at the next track day but I think this problem is solved with a good safety margin.