I don't know what wouldbe involved. I personally work with the original unit and know Vsig "decently".
Could a novice do it in Vsig? If you learn how to use it.
It's not about settings here; it's about the algorithm structure that should be similar to the analog structure of the original unit.
It's a fairly complex learning and developing process any human can do, provided passion, time, will and the right tools.
Ask your friend about his "tweak".