I used a small gizmo called Midi Merge (which merges two Midi signals into one), and I'm able to simultanaeously use the H7600 in my MIDI chain (which requires THRU) and VSigfile, which requires OUT. Isn't MIDI THRU supposed to always send what also goes to OUT? Seems like it doesn't. I'm fine now, except I need Midi Merge.
Also, any ideas why VSigfile only sees the H7600 if its ID is set to 1?