I was suprised also with the very tight SD on FPS that Shawn didn't uniform primer pockets or deburr flashholes. I would think that would have a pretty big effect on the powder burn and thus the velocity.
He also didn't think that neck turning helped him. I have a buddy who is a Ranger sniper and he turns necks on most brass, really got his eyebrows to raise when I hold him it didn't help him
But, the video does give a bunch of practical help and a place to start. So I have a plan and will work the reloads and see where it leads.