I think ultimately I simply wasn't paying enough attention to the shape of the blade, and not taking the time necessary to do it right.
I finally decided to start from scratch - even going as low as 220 to deal with reshaping the point a bit - before moving up through 1000, 4000, 8000, and a final touch up on a 0.5 micron abrasive sheet (
Lee Valley Tools). I'm currently waiting for both a barber hone and a C12k to arrive, but for now those sheets are doing the trick.
Along the way there were plenty of circles, far too many x-strokes to count, and once I felt I was on the right track I finished up with a 4k/8k pyramid.
All of which I had done before. I think the difference was simply patience and focus. :)