Maybe putting things into proper perspective would help.

I rotate my tires side-to-side during the race day and find that this does a very good job keeping my tires reasonably even. RARELY do I find the tires to be even .25mm off from each other after a heat where they started even, but let's pretend I did.

.25mm is roughly equal to 1 hundredth of an inch. That's damn small. NOW, divide by two because that's how much a .25 diameter change affects relative height of a corner. So now we're talking about .125mm or 5 thousandths of an inch. That's REALLY damn small. Can that difference be measured in tweak? I'd offer that it's unlikely with any but the absolutely most sensitive methods (which I'd argue my scales to be) and maybe not even then.

Our ride height gauges are wedges with the different vertical measurements spread out along a surface that isn't terribly far from horizontal. Because of this it tends to make things like a quarter millimeter (.25mm / .001") look REALLY BIG because of that misleading-appearing spread. Again, perspective.

Back to rotating the tires relative to Chris' "sweet spot". I find that if I rotate the tires after the first round of qualifying (one heat "off" even wear) and then run them two more heats there (one heat back to even, one heat "off" wear), then rotate them back again for the main that my side-to-side wear is generally very very close. Is there a "sweet spot" as Chris posits? There probably is, but I keep the difference to such a small level that it SHOULD be inconsequential.

My "routine" between heats includes tweaking, and I tweak for how the car will START the heat. I don't believe I see enough tire wear to make a substantive difference in tweak and/or handling, but even if I DID my car is starting the heat as "on" as I can make it and if the car changes it does so gradually (and similarly) each heat and would be easily compensated for. It's all going one way. If you were trying to "lead" the sweet spot you'd have the handling going one way as the wear caused things to head toward optimum, that brief moment of absolute perfection (because you WERE driving like a star and didn't hit anything) at mid-race, then the handling would go the other way as you departed that perfection. In theory.

I make any repairs or adjustments, rotate tires (if due), tweak the car on my scales, pookie the tires, go race. In that order every time.