Andy,
FAR 91.119c states that we are not allowed to fly within
500 feet of people, places or things, Except as necessary
for takeoff and landing.

If I find myself at or below 500 feet at the 1 mile
cylinder, I am allowed to continue my descent to the
field and make any appropriate pattern, including no
pattern to complete my landing. I am not allowed to
dive to within 500 feet at the edge of the cylinder
if there is any people, places or things there.

I don't think I need to restate what the low pass involves,
but just how far is the gate crew from the finish line?
500 feet? In most cases that I have seen, the gate
crew is sitting at the start of the finish line.
Just one more reason to go exclusively with the finish
cylinder.
JJ