Let me try to jump on this roller coaster ride.
First, I don't enter chords from xml, so perhaps I am not really getting the point here. But assuming we are talking about midi play of the chord chart, BIAB will interpret what chords you enter and play something different each time you hit play. That is the way the program works - auto accompaniment generation not midi playback. So you really don't have any easy control over voicing of a chord or whether or not BIAB plays a third against your A2 or Asus2 or A9. In addition to that, BIAB is not a notation program where the chord chart is explicit to the playback. The chords drive the accompaniment engine. This is all. So I think you guys are over analyzing this whole thing. But that may just be me. So carry on.
I know what you're referring to, Dan, because I've heard enough of BiaB's slight deviations from the chords in the Chord sheet window in the arrangements that I've used it to generate. While some of these deviations have been acceptable to me, others have not been acceptable, so I simply generated another arrangement until BiaB produced one that didn't have any unacceptable deviations.
The issue I'm addressing in this thread, however, pertains to the actual chord names that show up in the chord sheet window BEFORE I click on the Generate button to create an arrangement. If those chords are not the same as the chords in my XML file, then I know I'm going to have issues with the arrangement. For example, putting a standard A chord over a note that isn't in a standard A chord (a B note) is just not acceptable, just as putting a D chord over a C note isn't acceptable either.