Fair comment Click and thanks.
The heavier vehicles hadn't crossed my mind but make sense. But actualy heavier with alloy engines instead f cast iron, graded panel thicknesses instead of boiler plate and plastic where once was metal ?
Yes, brake friction materials have moved a long way forward and are more abrasive.
Not so sure about warping (yes I know it happens) but surely a truer test if this is a concern is a runout limit, not just thickness.
And certainly have seen cracked discs (automatic change).
Bedding in ? Was the day when it was common to bed in new pads. Run for a few miles with foot resting on pedal and dire results if you hammered the brakes hard until they did bed in. Brake fade only rivalled by old mini drums.
But the safety issue does come into it and can imagine the no win no fee lawyers having a field day with brake fade accident after a new set of pads was fitted and the discs were out of tolerance.
I'd not recomend anyone not following manufactures specs but I don't have to like them