When people are throwing the jab with bad intentions, I've found this difficult. Any pointers?
For starters, I don't believe this or any technique has 100% effectiveness for anyone. I think if an attacker is going to throw a jab, it will always be as "crisp" as possible, although less powerful than a wound-up punch. Catching a glimpse of an incoming jab and getting the hand up in time to catch the punch is certainly not easy, but with more practice it becomes more viable. There is certainly an important pointer that didn't come to mind as I wrote my post; a same-side step back should occur simultaneously with the palm stop, grab, and wrist grab.