@mijostyn , as long as the "loosened tolerances" are not due to damage, they should remain within the range of adjustment by the cartridge builder, and it therefore it should be possible to rectify the issues if the manufacturer accepts cartridge being returned for inspection / readjustment.
Some cartridge designs (certain Sonys come to mind) are not built in a manner that facilitates post-adjustment, but these are the exception rather than the rule.
Regarding Allearts' published specs, they may be beyond what one would expect to see in normal production; but presumably those specs were measured by using a test LP(s), and it is clear that there are substantial variations in test LPs from various labels.
The same cartridge will spec quite differently simply by changing the test LP. Occasionally cartridges are returned to us because the owner measured them with their test LPs and found issues, while we measured those returned cartridges with our test LPs and found nothing wanting.
As one publicly documented example, please read the following thread on Audio Asylum.
https://www.audioasylum.com/cgi/t.mpl?f=vinyl&m=974176
Same cartridge, different test LPs, different specs.
Therefore, if a cartridge manufacturer finds a test LP that fits their designs like a glove, I suppose that it is not impossible that fabulous specs may be obtainable (smile).
PS. I also recall recent reviews of the same cartridge by a British publication and a German one, and the frequency response was different in those two reviews, but this could be caused by the location of the test tracks (due to the pinch effect).