I might say
If you just want midi and to be able to enter "Any" chord then you could use RapidComposer as a standalone or as a vst in Biab.
Biab-RapidComposer-Ample Bass Win/Mac
Video Demo

I might say
You could use Studio One Chords from Biab Plugin then move the tracks in and make them follow the chord track as Melodyne will correct the chords in the tracks (though not sure how many chords it has).

As you say midi would be the way as you would need hours n hours of realtrack recordings to cover George's chords even though it's strictly rhythm.
You can create a UserTrack with all the chords and see if it plays the corresponding chord or substitutes for another, but as I just recall it maybe still a bit screwed up that way.

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