+1
When I created up scripts in Reaper it would just "randomly" pull out the same chord sections from the source files and put them together to match your progression.
I think with Biab things are already mapped out in the ST2 XT2 for what type of playing can be used where rather than just randomly pulling out any sections from all of the source files.
I think there is enough intelligence in Biab to make this work.
I showed this with using the current version of the BB Plugin/Plugin Standalone how the sections can be pre made up to suite.
I showed how Biab can play the rhythm tracks and the user can play an instrument with the right hand of the keyboard using vsti or their keyboard's instrument.