The BMW tech I talked to said worn CABs are the primary suspect for feathering on the inside edge. My 325i had bad CABs (not horrible, just worn) and my tires were feathered and had terrible tire noise.
My ZHP has bad CABs (again, not terrible at 50k miles) and my tires are already starting to feather and I'm getting the woo woo woo road noise.
Mind you my car feels tight-- no wondering or tramlining problems. The only way I knew the CABs were going was the felt/heard, "pop" when you stab the brake at low speed and the BMW tech telling me about the feathering (which wasn't bad enough for me to notice yet).
The tech said replacing my CABs will stop the premature feathering, but I'm obviously stuck with the noise until I get new tires.