You may be right. This technique can be made more flexible by avoiding layer opacity and painting to layer masks with different shades of gray. This has the effect of differential retouch opacity for every part of the image.
If you inspect the output of PortraitProfessional (www.PortraitProfessional.com
), you will find that they mostly lighten the dark pixels. In fact, you will be unable to use their built in tools to darken the light pixels. So their lighten is variable, but darken is fixed.
Imagenomics Portraiture is great, but it is not (easily) flexible as far as affecting some areas more than others.
My intent was fast not necessarily quality. But, could still do still do per pixel brush work with layer masks with this technique and get huge variety and nuance.