I am trying to establish ONE FACT:

Are there TWO rotor wear limits published by BMW or ONE????

(nachilus- your post is the logical application of a single wear limit...but OP is being told stories about two limits...and rayxi is making up stuff out of thin air)

I am only familiar with one limit, the minimum thickness that is stamped on the disk. Not saying BMW doesn't have two numbers, but I don't have a manual or service bulletin to know that.

I personally never trust the assumed wear rate, and so if they are anywhere near the minimum thickness or will be by the time the new pads are projected to wear out, I just replace the rotors. I usually just replace the rotors anyway, to get the benefit of a better friction surface and reduce the chance of any pad noise issues, since turning rotors went out of fashion.

so that might be why my fronts have been squealing for about 8k miles now. they swapped pads but left the rotors. i tend to threshold brake, so it makes sense.

Agreed.

Well for my situation, both sets of new pads are already in place. If I called another dealer and asked just to get rotors done now, that wouldn't qualify for "done at same time"... and of course they're not at minimum so I can't even argue that.