I could be wrong, but I think the EGW dovetail mount is the same as the Springer Precision 75B Shadow mount. If it is, it will work fine. I have Springer mounts on three pistols and have used them in bullseye matches as well as 100 and 200 yard demos. I had to add a 0.010" shim to a similar mount to tighten it up, but it was fine after that. I used them for exactly the same reason--not sure if I wanted to cut the slide. I have slide cuts on P-10C and P-10F, but not on P-09, 75B, and 97B"E". Those all have Springer Precision dovetail mounts. I used the Springer Shadow mount on a P-10F until CZC had the OR plate available.
Joe