Utility of Key Lock Chord Notes/Extensions

I’m working through the paid tutorial video and have a question about how others would use the Key Lock Chord Notes or Chord Extension features.

Maybe it’s meant for folks who have very little keyboard ability or theory background - I just don’t see how I would use it. By no means am I gifted piano player, but for someone who already knows how to construct triads and extended chord shapes, why would you use it?

I’m certainly no expert, but it seems like it is there to allow someone to experiment with melody creation in a piece without a risk of going out of key. Obviously chord extension lock has a bit more risk allowing you to drift a bit more.