To describe skating force as constantly changing and therefore any setting will be imperfect, is accurate but deceptive. It is accurate that skating varies with groove velocity and offset angle, but deceptive to apply the word perfect to the physical playing of a phonograph record.
I don't adjust AS by seeing how the stylus behaves in a blank groove. That seems pretty stupid. If you observe the cantilever from the front while your "typical" music is playing, and repeat this observation, you might get an idea of the error your headshell position is to the centering of the cartridge. In a perfect world your cantilever should be centered over the groove. Antiskate is a force applied to the arm in an attempt to do just that.
What is groove velocity? The velocity of stylus deflections (bouncing off side walls) in-groove. Since the groove is constantly moving it's the job of the arm to be both a stable platform for the cart and a perfect follower of the groove as it moves toward the spindle. Why the uneven tip wear if such is the case? Having a poorly centered cart is to encourage channel imbalance - uneven cantilever deflections with respect to L and R.
If someone hasn't heard channel imbalance due to AS, then they've been using heavy trackers or lack powers of observation. This is obvious with low VTF carts where channel imbalance is more dramatic and immediate. I think you'll find, there is no completely right answer. With lower cu carts you're choosing between physical centering and increased torsional affects on the cantilever from AS.
fleib