Yes, "zoned CAV" was what I had in mind when I wrote "constant linear velocity" for modern hard drives: the idea being that in the areas where there's more media passing under the head, you can have higher bit density than in the areas where there's less media passing under the head. But as you point out trying to optimise this on a per-track basis is horribly counter productive.
I probably should have said "semi-constant" linear velocity (the "zoned CAV" term didn't even come to mind until you pointed it out).