I just read the description of the the Palmer track, and he advises using stock exhaust because the track is in a residential area.

Two things come to mind.
1: How many bikes in your event ran a louder aftermarket exhaust?
2: Which came first, the track or the houses?
Just a thought.

I'm pondering how to work out doing a session later in the year. I have family in Ma, and Im sure I could make it into a mini vacation