Hi Lee,
now that's an interesting thought.
A QY100 as a soundsource for OMB.
Do you actually own one Lee?
The last one I had was the QY20 & the larger QY700, but that was years ago.

Doc, I doubt it's still available, but, Yamaha used to have an XG softsynth. Latency was terrible so couldn't be used for realtime playing in OMB. For backing arrangement, maybe it would work.

If I'm not mistaken, you've actually tried OMB before??
best wishes
Rikki