it is interesting, but the same (freehand) feature was implemented in RapidComposer years ago, together with the 'Line' tool. The 'Freehand' drawing inserted musical notes (snapped to the current scale or chord) on the curve that you were drawing, but the feature was removed temporarily because at that time I did not find it useful. I did not get the results that I expected. This will have to be revisited soon.
The rendering of the curve is ugly, sorry about that, it was a work in progress:

Thank you for your input, and links!
Attila

