Am sure Klippel has calibration standards to ensure consistency. Should not have to rely on ad hoc circumstances to get comparable results from the same measurement rigs. Can definitively state that testing 2 different speakers is not a solid approach (even if exact same brand and model). Otoh, as we have seen, slight differences in mic setups can cause significant measurement diffs. However, you do not need a Klippel to know this but am pretty sure it is even more of a challenge…I suppose it confirms Kippel is consistent in at least two locations by two users.
This is why I readily accept close results within reasonable tolerances. Even if you had 2 systems in adjacent locations testing the same speaker with the same Klippel measurement setup, would still likely have slightly different measurement results. This could be due to mic boom diffs or different mic surrounds or some other difference in the measurement chain. Distortion measurements are even more susceptible to small system differences.