Well, I frogged my WCTP hat last night, turned the yarn into nice little cheeses, and started again on 4mm needles.
I've only done ten rows so far and I'm already better pleased with it. The fabric on v.1 was dimply and I thought it was something I was doing wrong with my stranding/weaving technique, even though it was dimpled before I started the skully part of the chart. Now I think that perhaps the yarn didn't like being worked at such a tight tension, and the dimples were the expression of that unhappiness.
The new fabric is nice and firm without being stiff and I'm not getting the hand cramps that I had put down to the onset of Autumn aggravating my fibromyalgia. So - Result!
A lot of my frustration disappeared along with the hat and I'm feeling optimistic again. If I had finished the hat as was, I would never have been happy with it.