Dave, I agree that G + E (below) would be E-minor because the interval from E to G is a minor third. I also agree that G + Bb (above) is a G-minor chord for the same reason

The scenario I am asking about is something like Bb + G (Bb below G). For example, play Bb with your left little finger and G with your thumb. If you added the fifth (D), you would have G-minor. So even without the fifth, you still have the makings of an inverted G-minor chord.

Whoever programmed the PA50 agrees with you, because does interpret Bb2 + G3 as Bb6. But IMO sixth chords are comparatively rare. (even when they come up, you can usually substitute a major chord). I prefer the Roland's flexibility of being able to trigger minor chords by playing the third below the root because it allows me to play more different chords without changing hand position.

This gets back to my original question. Do you have one of the new Korgs, and are they programmed the same as the PA50?
Thanks for your input,
Ted