If it can be proved that the profile is extracted with an acceptable error (x,y,z sampling rate and accuracy) or referred to such proof, then it is a correct way.
However, there will be a necessity to cut-off the long wavelength of the nominal form (sphere), which will be present on the definition length. Roughness and waviness of free form surface, such as sphere, are easy to obtain with a white light interferometer (light microscope).