SPHARM-PDM runtime

Hello , i’m using SPHARM-PDM module in slicerSalt to represent the tooth using spherical harmonics but the run time for the parametrization part is taking to much time (one hour and sometimes more ) for only one tooth. Is it normal or there is any way to make it faster, im using 500 iterations for the parametrization part and 20 for subdivisions and 20 degree as spherical harmonics degree.

thank you in advance.