Hidden controls
A tiny neural net classifies each traced loop (circle, ellipse, rect, star…); a geometric check accepts the snap only when the exact shape fits within tolerance.
Smoothes the bezier curves more — usually best left at a minimum.
Thin ribbons (the sample's birds) are traced down their middle and drawn as a single stroked path, instead of outlining both edges. Experimental — off by default.
Downscale large images before tracing (speed vs. detail). Change re-runs the trace.