Not trying to badmouth anybody here, but when it comes to grip cracking, it's mostly a fitting issue.
I've installed and used quite some SV grips using factory procedure and no one ever came back with a crack.
I saw some cracked SV grips, in all occurences they were second hand fit, other brand frame and /or shot without the front screw in place (Yes, I know some people claims there's no need for the front screw with X or Y brand).
I'm not saying it would not happen, i'm just saying that the variables are numerous to reject the fault on the product.