At the risk of repeating myself...
How do you have a SLAM FIRE on a CZ-97B unless 1) the firing pin block has been removed, or 2) the firing pin itself is broken and jammed in the breech face?
The gun has an inertial firing pin, and just having the slide slam forward is NOT sufficient to make the firing pin jump the gap and hit a primer. (Believe me, if that were the case, every time you fired the gun, your gun would go full auto!)
The gun also has a firing pin block. Every time the slide moves to the rear, the firing pin block plunger drops and re-engages the firing pin block. The firing pin block can be deactivated only by pulling the trigger. If you pull the trigger BEFORE the gun is in battery, it won't deactivate the firing pin block, and the gun can't fire. If it then goes into battery with the trigger pulled to the rear, it won't fire, either.
Some else said it, but I'll say it too -- it isn't possible -- unless you have several catestrophic failures at the SAME TIME. And if you have those problems the "safety modification" is going to do ANYTHING to prevent the problem...
You guys either don't understand how the gun you're talking about works -- or you've learned something I simply don't understand. (It won't be the first time someone here knew something I didn't understand...)