Okay, my balancer arrived, and after assembling it and trying my twelve brand-new DJI props, here is my conclusion: About 25% seemed nearly perfectly balanced, about 25% were detectably out of balance, and about 50% were slightly out of balance. None of them were so far out that I would have any concern whatsoever flying with them, but being a bit of a perfectionist, I corrected them all.
I used some stuff called Bondic to add a little weight to the top-side end of the lighter blade. My thinking is that since it is actually the underside of the blade that "strikes" the air, and there is a relative "vacuum" on the topside, any disturbance of airflow would have slightly less effect. I may be mistaken about this, so I welcome input from anyone more knowledgeable who can guide me in this thinking.
Bottom line... the new, stock props should be fine, and I don't know that all this fussing will make any material difference.
~ Russ