Thanks for the clarification, John. As you said, I took the lens out for a quick spin that day. I'd previously seen reasonable complaints here that posting of reduced-size photos doesn't really show how well a lens behaves. Nevertheless, I should have left out the pixel-level crops from my posts given the limitations of the technique I used in taking those photos. Including them at all was counterproductive, as they primarily reflected technique rather than lens quality.
In terms of my own skill set and practices, I think one problem here is that somehow I all along ignored the technique (which I have heard of before) of using diffused flash in the field to freeze motion for macro shots. Indoors, sure. Fill flash outdoors, sure. Outdoor macro - no flash, just absolutely minimize vibration if I have the right setup with me. It's funny how we get into mental ruts sometimes.
Nevertheless, I have all the needed tools in my possession (flashes, diffusers, reversing rings). Your suggested approach seems like a useful technique to start practicing now for those times when a tripod is not desired or practical.
