I am re-opening (unresolving) this can of worms.

I never found a solution to the problem.
As I mentioned above, I was finally able to hear a mMaj7 chord while working on another problem.
But I never figured out how to get a mMaj7 chord to play on demand.

If only a PGMusic techie would step in now and say "Sorry it can't be done, we're working on it",
I would leave this alone. But until they do I will persist in trying to figure out if there's a solution.

I just finished experimenting with a bunch of RealTracks and Styles.
None of the Miles Black RealTracks worked.
None of the Mike LeDonne piano RealTracks worked.
None of the Kenny Barron piano RealTracks worked.

_JAZOR60 Organ warbling badly, BUT I could get a mMaj7 !!! (Mike LeDonne on organ)
I used the trick to fix the warbling --> Auto-fix sour notes disabled.
BUT when I did that, the mMaj7 chord disappeared !!! ARGHHH !!!!
I did not regenerate!

So in addition to still needing to resolve this, there are obviously some serious bugs happening here.

A BIAB user for more than 30 years (if you can believe it) !