Here's another factor that may or may not be very relevant: RIM WIDTH.

Velocity makes the Major Tom wheelset for CX and it has a WIDER rim that they say is good for CX. I hadn't heard about wider rims for CX before. From what I read they're talking about better glueing. ...But better gluing relates to stability as well as plain old security so the tire doesn't roll.

Conveniently, a friend gave me his old Major Tom wheelset so I could give it a try to see if it helps my wonderful Dugast 30's stop folding over at my desired PSI. Or if it at least helps me run a few more lbs softer than I can now on a narrower rim.

Oh, another thing I could probably do better with: gluing tight all the way out to the edge of the rim. Sometimes when I torque my tires back and forth laterally they open up a bit of a gap at the rim. That can't help w foldover, right? Apparently this is why rim bed shape is a thing. Whew. I wonder if there are fixes after a tire is mounted -- like flowing in more glue along the gap and, um, inflating or deflating to whatever setup squishes the tire outward the most then let it cure. ...Might grab the outer edges of the rim that way?