I am not 100% sure this is a bug, but it is not behaving like I would expect.
- Set Keys Lock to Chord Extensions
- Select C major scale
- Add B9(b5)#9 to pattern 1
- Click on B9(b5)#9
- Inspect keyboard at the top (where the chord extensions are shown with the green lines at the bottom of the keys)
- The Keys Lock notes contain F, A, and D
- The Keys Lock notes contain F#, A#, and D#
It seems like Keys Lock Chord Extensions is ignoring the altered chord tones.