Air down tires

so of course airing down is good for off road, but my question is when going out on a decent trek and I'm carrying some weight in the bed (ie camping shit and tools). How much is it safe to air down or should I even at all. I ran the same weight through a sand wash on my way out of camping, I had been running the same wash all weekend and of course I noticed a difference but I wondered if I had kept my tire pressure at 35 if it would have been better.

My off-roading has mainly been at raptor events and I usually air down around 35 and make a run then go again at 30 and start adjusting from there. I ended up running 28 at TRR and had no issues. Some go to 25 with no issues also. At raptorfest I ended up leaving at 30 but did pop a bead around a corner.

I think it really matters about the terrain, the conditions and your speed so every situation is going to be different. On sand dunes, I've aired down to 14 and even was jumping without issues but I was keeping straight lines.

I run 25 psi on dirt forest roads here in AZ. Many of these roads have large rocks and I run them hard and fast. I'll often air down to ~15 when I'm running on jeep trails and over big rocks and boulders. I occasionally head to the dunes and I run ~15 there too, again, I drive hard and fast, drifting, donuts, jumping, etc. 35k miles with much of that off road, all of it hard and I'm still on the original tires with no problems, no flats, no blowouts, no popped beads.