There is no such trick to not trigger the penalty anymore, that's fixed.
Also, locks can cast while moving if they don't take either AV or MF instead. KjC is great for high-movement fights, but there is quite a few times where it'd be better to take AV for pure, unadulterated dps gain, or MF to gain range on AoE to do more damage there. Not all locks have KjC by default.