Perhaps, our Service Techs take the belt and braces approach – and are very thorough in what they do?
If you think about it logically – it wouldn’t be possible to model bearing failure on a steering stem, as a function of mileage! (hypothetically, the bikes could ride in an almost straight line with no rotations!).
Fundamentally, if the service team are going into an area to inspect/adjust for preload settlement etc – at a major mileage service interval, the thorough approach is to replace – whilst you’re at it! Perhaps this is a positive approach?