Question

This has so much potential to help us composers making songs, with some chord progression assistance!

Have a look at AutoTheory by Mozaic, and Native Instruments Komplet Kontrol light guides (and some of their instrument plugins), E-instruments Session Keys Animator  to start with. All which I use but sadly work outside the DAW or are very restricted within my DAW (S1). :(

Answer 1

A good example is Chordz - CodeFN42, it's a FREEWARE plugin and it's year ahead of of native MIDI Chorder from S1, for example you can click each key and select in a list wich chord you want to that key separately.

Answer 2

Also, please take a look at the Chordbot App for both Android and iOS.  Functionality like that in Chorder would  be Awesome.