Can use just use a minor chord and add the extra note in playable realtrack mode ?
Just adjust the PRT volume to match the audio level.
That might be workable.
ThomasS has a good suggestion too, to use alternate chords with a slash bass note.
I'm just really surprised that workarounds or fiddling with all kinds of settings are required to
get a basic 'This Masquerade' chord happening in BIAB.
It is 2024 right?