I think it's self explanatory. The use of the ZS is to alter tonal values to improve an image. 99% of the HDR images I've seen use the technique because it exists. I can't think of a single over-manipulated HDR image I've ever seen, which wouldn't have been better left alone.
If HDR is used correctly it is used to do exactly the same thing, improve the tonal/colour range of the image.