Digital Light & Color

If I have two imperfectly aligned images focused at slightly different positions, what is the best way within PWP first, to align the images and then identify the sharper regions in one to transfer (by cloning?) these regions to the other image?
Is it feasible have a cloning condition "copy if sharper" analogous to darken only or lighten only? I can also imagine composite being used to align two images and then combine regions based on the sharpness of one compared to the other.

Focus stacking is a complicated and specialized operation best performed using software designed especially for this purpose. Personally, I use Helicon Focus or Zerene Stacker. Focusing at a different distance changes the image magnification so simply cloning the sharper image does not work. Even focus stacking software has problems with complex foreground elements such as blades of grass or branches which tend to generate halos in the final image. And of course any subject motion produces ghosting.