Understood. That command in Surfice is very primitive, and is only designed to give an approximation. I am not planning on making that algorithm more sophisticated as I think the number of parameters that could be tuned is huge and beyond the scope of a visualization tool. Surfice is open source, so you can always tune the code for your needs.
If you prefer Matlab, you can use the MRIcroS code:
https://github.com/bonilhamusclab/MRIcro...