All I could do is test my MIDI keyboard to see how my Ample Gutar collection VSTi handles it. It can output as a MIDI guitar -- ch.1=string1, ch.2=string3, etc). It works with my DAW (Reaper).
Results: it does not with Notion.
Keyboard connected, even with multi channel guitar enabled, Notion fails to input MIDI channel change outputed on my keyboard to trigger the other guitar strings. It could only trigger one string.
However, I can program rules with Notion that triggers the proper string on my guitar VSTi. The Only notation software to be able to do that.
It does that through keyswitches, but not channel change. This is where it lacks.