Maybe something like this. Click "+" generates a track linked to original, click one more time, creates a new sub-track with another generation etc.

And another thing, with this logic, partial BAR FREEZE can be achieved in this manner: Regenerated tracks could have "FREEZE" icon ---> Under "Bar Option"
You would do mute/unmute of that frozen track in any "section" of the song, From bar "Y" to bar "X" etc.

I admit, this is not a well thought out idea... just an idea that could solve two big issues.