Fortunately, my "finishing rinse," which was originally designed for the smooth skin of my model photography, does a fine job here. It preserves the edges I want and smoothes contrast elsewhere, creating more "dreamy depth."

And with no blur filter, mind you. Any of the Blur or Sharpen filters would throw out all the flexibility to double-check opacities as the image builds up. Hence a completely different edge management solution was needed, to participate in development rather than lock it down.