I just added the EZD rear sight to my 97B. The rear (harmonic dampening) set screw is in contact with the slide, just at the very end above the hammer in the hammer notch. It's like you said, the screw is not entirely on the slide. It sits about two thirds on the slide and one third aft. The aft 1/3 is in contact with nothing. It tightens up fine, though.
The sight picture is very good. I like how it looks on the pistol, too. Got some new LOK thin bogies to boot, and an Ultra-Lite Kit from CGW. That CZ97B is a flat sexy pistol!
Stephen