500 mile start/stop break in is for dumb ass americans who have no concept on how to drive a manual car.

If the clutch is decent, it was installed with a newly faced or new flywheel, minimal break in is required.

And worst that would happen if it wasnt up to the job, it would slip and you'd now it needs more time.
Problem is after a clutch does slip, many idiots keep abusing the life out of them until they are completely and utterly destroyed...then blame the manufacturer and expect a warranty on it.

Reading the US forums, there are more "faulty" clutches there than anywhere else in the world !!