Hiya cousin mark and thx for your thread. In almost 10yr shooting mostly cz's,and the slide stop has broken once in a shadow sp-01,and twice in two different tactical sports. Of guns bought new the TS's always came with an extra two slide stops. So I suppose cz is at least that aware of the fact. I shoot mostly reg velocity ammo and never reloads. Never had a slide stop break in a gun that also gets fed a little HD/plus p ammo. Some competition shooters here using power factor ammo can chime in. Didn't keep a spare one till it broke,but always have a spare now,and always take at least 3 guns an outing.
Suppose you can go to the forum lobby and search the breakage. And you might lose a stage if it happens in competition. But no worry about the slide landing in your forehead, part of the broken stop will just lock up the gun,a symptom similar to how sudden failure of a trigger spring. If you don't have the proper tools you can scratch up areas pretty bag, think rubber tipped needle nose and non making punch got mine sorted out. I've not heard it being a urban legend story yet. Its about as legendary as a motor going out in a vacuum cleaner, or car not starting. Be well.