Discussion: Dealing with sand monster two-tracks

I'm racing in the Northern Pursuit this weekend, a 24-hour AR in Michigan. The course will feature many two-track options, some of which will be sandy and some that won't. From your experience, would a two-track in forest likely have a lot less sand than one exposed to the elements or close to water drainage? Is there any way to increase my odds of getting on a fast two track, which I would take even if the distance is much greater?

Also, what air pressure would you recommend in a 29" tubeless tire with a mix of hard packed and sandy two-tracks? 160 lb. weight. 35 psi? I think 40 is max recommended. Or do I go down to 30 to help get through the sand and figure it's still plenty fast on the hard stuff.

My experience with tire pressure in snow is that you don't reap any benefits in traction until you get down to 10-15 psi which I'd think is similar to sand. Given that you'll try to stick to hard packed surfaces and minimize you're travel in the sand I'd optimize for that.
As far as where the sand is, good luck. In the '07 MIX we chose a route which followed a creek that turned out to be all sand. We saw it and turned around to take the much longer paved road option. Those that followed the sand route later told horror stories about pushing their bikes for 5-7 hours...Tough to do while constantly swatting mosquitoes.