Power Meters / Powermeters (SRM, Powertap, Quarq, Ergomo, Vector, Stages, power2max, P2M, 4iii, InPower, Cinch)

This statement from the p2m website:

Do I need to recalibrate my power2max if I change the crank or chain
rings? Changing cranks or chain rings does not affect calibration. You
can also use oval chain rings (e.g., Rotor Q-Rings, Osymetric, etc).

My experience tells me this might not be totally true. Anyone else able to comment?