So, if it is possible to do that, it somehow must be possible to extract the notes, sort them per channel and to write the information of wich transformation is used (Pitch Portamento, Note Portamento, value of changing and so on) . Put that to a tracker and then allow to optimize things.
A couple years ago, there was being prepared a mini-tracker for SID-sounds in Atari 8-bit computer by Swiety/ZELAX, but unfortunately, it wasn't never finished... :(