No, the problem is that in doing my best base polish ever, I went too deep and removed too much metal, as this current stone (#1200 iirc)is bringing out the hamon, and it's clear I've polished away much of the finer details. The root cause of that, however, goes to the pre-heat-treat final grind, which I left thick in order to prevent edge cracks and warping. It worked, but on this side, at least, the price is a less-than-perfect hamon. I need to, in the future, either grind closer to the final shape before heat treatment, or use a different edge geometry, one that takes off less meat around the hamon.
Still, there's the other side, and this is, after all, the test piece, not the pattern-welded best-of-class coming up next.
Once I finish up the base polish on side B, the rest of the stones should go fairly quickly.
At least I'm finally done with side A.