Warranty voided yes, issues that don't occur in regular factory sebenzas... doubtful. This has performed exactly like the other five sebenzas I've had over the years. Smooth, rock solid lockup no play. Lockup hasn't changed in the two months used. Continues to get smoother as it breaks in.
I understand the blades are cut then stonewashed but I've never heard of CRK blades being "ground" to fit the lock bar.
Now I may have it totally wrong but...
The bushing and washers are hand fitted which slightly adjusts lockup. The blade or lockbars are not modified to adjust lockup, they are precision cut. At least that is what I got from their shop vids. Which is probably why I can swap this setup in the three different small frames I have and lockup, centering and action is exactly the same.