Y'all are a bit more "precision" than I!
I've miked a few virgin-brass cases (.220 Swift; .243) and found they were a tiny smidgen shorter than spec--and so I quit worrying about that particular issue. "Let 'em grow, I'll cut 'em off."
The issue of roundness never occurred to me. I always chamfer the mouth of the neck. Seems to me that (carefully) seating the bullet does the same thing as running an expander through it? I gotta admit that so long as my groups are notably inside an inch for 30-caliber and around 1/4" to 1/2" for the "small stuff", I've always been satisfied.
Were I shooting competition, I guess I'd go "ultra" on precision and uniformity...
Definitely concur about checking length and annealing and suchlike after some number of reloads.
Part of my deal is that the majority of my brass started out as factory-loaded ammo, or was range-scrounged which I full-length resize before loading.
Art