If the manufacturer claims tolerances of X but the CF shaft you get exceeds what the manufacturer represents, that would seem to fall under the guise of a warranty issue.
Where do you see the manufacturer's stated tolerance for their shaft? You nor I know if it's within tolerance as it's not stated unless I missed it somewhere. All I'm saying is that 0.09mm is very small indeed. To the point that it's probably well within the acceptable tolerance of CF. No material is perfect. No mass produced product is perfect. No blank is perfect, be it metal, CF, wood, plastic, glass, etc.
When the manufacturer says the CF shafts are built not to vary in taper but the shaft does, the manufacturer has an obligation to repair or replace the shaft to the tolerances they stated in writing. If that isn’t a defect under the manufacturer warranty, then what is it other than an oops? All you are doing is making the manufacturer back up what they promised and failed to deliver. Let’s see how others feel because all the shaft CF shaft owner would be doing is insisting the shaft builder fulfill what they stated their product would be dimensionally. I think I’m right but you don’t.
They say the taper doesn't vary, but in reality when dealing with real world tangible objects there is nothing that is perfect. That's why we have tolerances. They tell us if a product is within spec. Nothing is perfect, but tolerance tells us if it's "close enough" to perfect. They don't state a tolerance, so you nor I can say it's bad or good. Them saying the taper doesn't vary is marketing. If you take a microscope and zoom in 1000x CF will probably look like sandpaper. All those little peaks and valleys are variations in taper. This sounds silly but I'm just taking it to it's logical conclusion. Unless magic is real and they conjured the shaft into being with a 1000 year old wizard and the sacrifice of 10 virgins, no shaft is perfect. Real tangible objects are not perfect.
Just like Kielwood, maybe you have a bit more to learn and maybe shouldn’t be so quick to judge because the CF shaft being discussed was not built to the manufacturers written specifications how their shafts are built within strict tolerances that the manufacturer failed to do with the shaft in question. That falls within warranty or at least IMO.
As far as I am aware, the manufacturer did not state their specifications and tolerances, so there's no way you or I could prove if it's good or bad. 0.09mm is minuscule and is most likely within spec.
Could it be made with more precision? Sure. But you're not going to find NASA level precision on a consumer product churned out by the thousands. It's unrealistic. Say for giggles that Predator makes 100 shafts in a day. If they were held to a silly tolerance like +-0.001mm, they could make 5 a day. It could be done, but each shaft may cost $4000. No one would buy them and they would soon go out of business. Would 20 people in the world buy them over a year period? Maybe, but they will make nowhere near as much money as if they produced 100 shafts every day and sold them for $400.
Precision costs big money, both to manufacture and inspect. The consumer pays for that, and they are only willing to pay so much for a given product. This is how everything is manufactured.
