Hi Rutvik,

The option can be added to MapIcosahedron but that will have to wait a bit longer. But I am not sure that would be of any help to you. Your results would depend on the number of nodes you use for the icosahedron which does not tell you much about the warping.
To my mind, you should compare segment length change between spherical and warped spherical. That comparison does not have to be made on the standard-mesh version of the surfaces. If you want to get an estimate relative to the segment lengths in the anatomically correct surfaces perhaps you can normalize (scale) the segment lengths on the sphere by their lengths in the anatomically correct surfaces.
The programs SurfMeasures and SurfaceMetrics might be of interest to you.

I hope that made some sense.
cheers,
ziad