PS skin softening question

You can adjust the radius if you first convert the layer to a smart object.  However you won't have the option of inverting it, so you must do this before the high pass step.  I would assume that inverting before or after will make no difference, youi'd have to experiment to see.

1. Duplicate layer

2. Invert layer (you can desaturate if you want)

3. Convert to smart object

4. Filter > high pass

5. Change blend mode to overlay

Now you can go back and change the radius as long as you leave that layer as a smart object.