When did I say that manufacturers lacked measuring equipment? I don't remember saying that. All I meant is that with a single sample of a lens there typically won't be anything to adjust other than focus' reference to infinity.
Basically there's no way for a user to adjust alignment of elements if the lens barrel assembly has zero facility for doing so. The only thing the user can do is follow strict disassembly/assembly protocol. I think that's a pretty sane assertion.
The whole point of this thread is in breaking down the bullshit protectionist mysticism surrounding camera and lens maintenance.
Stop worrying about grain, resolution, sharpness, and everything else that doesn't have a damn thing to do with substance.