the drawing software is actually pretty simple and draws "plots", with each stroke being a single plot and the pen lifting after.

What that means is you cannot scan a signature and reproduce it, because the machine won't know where to start and where to lift the pen. We used something like documented here: https://wiki.evilmadscientist.com/Capturing_Handwriting#Capt...

This produces SVGs which have those individual strokes that the machine can reproduce.

jSignature looks interesting. I wrote something like that for capturing signatures on Android years ago, where you work out each plot until the user lifts their finger.

I wonder if you could recreate signatures by examining the depth of the ink where the person lifts their pen, since that typically has the largest deposit of ink at that point, particularly with a fountain pen.