I agree we need this, but it has to be done properly with a number of alternative layouts for simple to advanced level.

A good function that needs expanding is the chord builder "chord theory" section displaying chords for a given key on any root. You can click on each quickly in succession to audition a progression.

Its ok but limited; like almost everything in BIAB it's diatonic, not modal or chromatic. And progressions that modulate quickly or borrow from parallel modes aren't covered.

Better perhaps is the chord substitution dialogue box. There's Lots of intricate sequences replacing a simple II V I cadence. It's useful but diatonic and very "standard jazz" orientated.

If you're theory knowledge is up to it you can even alter the associated text file to include your own formulae. But it's very "1990" as far as user friendliness goes. No one works with software in this manner nowadays.

I think the latter text file needs to be worked up into a proper user interface and the preset suggestions more varied according to genre and sub-genre.