another account of blade play on a sebenza? NO WAY! they are the best possible knives ever
in all seriousness though the only knife Ive ever owned and used extensively that didn't ever establish blade play was a zt 0300. Ive literally used it like a fixed blade and its remained a rock.
The only other way to prevent lock rock is a carbidizer, but they only can do so much. after the "grit" per say of the carbides wear off, the knife usually has lock slippage instead of lock rock.
I think zt did it best by using dlc on the lock face. It never wears and Ive never had any issues.