I figured out the mystery of how I've been rolling my edges. I haven't been rolling them: I've been eating them off by mis-stroking on the linen.

I use VERY VERY light pressure. Even the weight of the razor is too much if it's a heavy razor. Even so, every few weeks, I'll screw up & do a bad stroke. A bad stroke feels like the nap of the linen is catching the edge at the end of the stroke. It's a very subtle feeling. What I must be doing, even though I'm not consciously aware of it, is failing to lift the razor completely off the linen before I start returning the blade toward me for the next stroke, so that the cutting edge just barely catches against the nap. All it takes is one bad stroke to completely destroy the cutting edge. It's very easy to do this.

Anyone else ever have this happen? For the time being, I've forsaken the linen entirely, using a homemade Latigo strop instead.