Hi everyone,
thinking about this, when BIAB treats a 2/5/1 I presume it does it for the key of that 2 5 1 rather than in the key of the piece. This is because you can of course have a 251 to any modal chord - for example you might get a 2/5/1 to the fourth of the C key signature - F. This would be Gm, C7, F major - non modal tone Bb. I presume BIAB would recognise that say F| dorian was in the key of Eb and voice accordingly?

Win 11 64, Asus Rog Strix z390 mobo, 64 gig RAM, 8700k