That's an interesting read.. it'll take me a while to digest it all.. but on first reading it sounds like it supports the original theory of this thread.
Here's a quote I found interesting..
Every gun and pellet combination that I have chronographed had one thing in common. If they shot accurately, they had a high degree of pellet stability, and those that shot poorly had a very low degree of pellet stability. In some cases pellet stability was so poor, that even when chronographing them at 10 yards, velocity spread was over 100 FPS; yet muzzle velocity was quite consistent.
That quote seems to suggest that you could potentially select batches by measuring velocity as close as 10 yards..
If I get a mo, I'll see if I can get my combro and pro-chrono giving the same answers at the muzzle, then move the pro-chrono out to 10 yards to see what happens to the readings.