Saw it a fair amount in my short stint at a tire shop. It was generally caused by low pressure and high speeds. I doubt airing down on FS roads and driving is going to do much to sidewalls but make sure you aren't pushing the speed to much. There are some roads that you can cruise on here and long periods of high speed with low pressure can cause issues with sidewalls.
If you plan to do this a lot, mention it when getting tires.
Yeah, it’s just never been something I considered… makes sense, but I think a little common sense goes a long way, like you said, hauling ass aired down… not just sidewall stress, but rolling your tire off the bead… we did that once trying to get up this steep narrow hill, and it didn’t help our cause… Finally got out of there, but it was a later night than anticipated
When I do air down, I don’t think it’s very hard on anything, considering I don’t air down a lot, often, and for sure not driving fast aired down.
It’s easier to just drive a rig that handles crappy roads well

a few years ago (after my s-10 zr2 burned down) I got a Jeep Wrangler, always wanted one, the second day I had it, I had to make my 3.5hr commute down the coast to work, that drive had me question my decision… just not used to it… yeah, that’s why, haha
After work the next day, a buddy I work with and I decided to go up in the hills and do some shooting, it’s a pretty tore up gravel road, nothing that would test a Subaru, just bouncy… half way up the first steep grade I hit a pothole and almost knocked my buddy out, he whacked his head on the roll bar, haha
When we got back to the boat that evening, I put the damn thing on Craigslist, at the end of that work stretch, I was driving a 4Runner home
Airing down would have helped a lot with that rig, but I’m off pavement too much to air down every time I leave pavement, I thought I was a jeep guy until I bought one.
Another time, when I was driving a 91’ standard cab Toyota (great little woods rigs but beat you up) I decided to go check the water clarity on a river up in the mountains, I didn’t think I was going to be fishing that day, but I had cabin fever from a long series of storms, I was dry and warm, drinking some coffee, but had my waders, bobber rod and bait if the river was fishable
I turned down the last little spur, maybe 1/4 mile to the trail to the river, and half way down there was a nasty pothole, and not wanting to spill my coffee, I went around it, and with the torrential down pour we had for 10 days, the ground was soft on the downhill side, and I slid down the hill… crap… long story less long, I tried a little before realizing my pickup was going to drop 20’ if I kept trying, so I left it there and started walking until I got cell service a few miles down the mountain… took a 1 ton ford and a Tacoma to get me back on the road without rolling… of course it was a boneheaded move by me, but those pickups were so stiff, I knew even going slow through that hole would suck… I don’t want a rig I have to air down to smooth the ride to tolerable, plenty of nice riding rigs these days, or you can make any rig ride pretty good with well thought out suspension