You could understand with the RealTracks and the 12key ones now that file size is a limitation so substitution is used, but with MIDI there's no issues with file size so they should try to cover more chords in the recordings especially for Jazz.
Even if you had an option in BB to snap midi to chord/scale notes would help.

I suggested a guide for manual snapping or an option to Snap Selected Notes to chord/scale, that could have a different color shade for root, chord, scale, out or passing note.
There could maybe an option to duplicate notes from existing chord notes for missing chord notes as you would do manually.