It's a bit like apple these days, they bring out a knew OS just about on a weekly basis with new fancy features, then apps stop working and developers have to work overtime getting another version of the app working for yet another version of the OS.

Now that Biab and BB VST integrate so easily with Reaper I can add any feature I need in Reaper with a script rather than have to ask to get it added to Biab, like the CHORD TOOL asked for, there are plenty of them made as addons for Reaper.
Unless you are using it for practice/learning or auto accompaniment the sooner you can get out of Biab the better.

The Midi Chords VSTi you can set it as default synth and it will be there all the time:

[Linked Image - Only viewable when logged in]

I remember making a Chord Picker Tool for Biab years n years ago, the same thing can be done with it to create a chord note input one.
Biab Chord Picker Tool
With AutoHotkey you can make so many GUI Tools for Biab without waiting years for something to be Added. So many things users ask for can be accomplished with it.
It works so easily by calling Biab commands and functions, Biab users shouldn't be scared of it, they should embrace it as millions of AHK users do.


[Linked Image from pgmusic.com]