I would like the ability to split a single existing markup polyline into multiple polylines at a control point. The 'sketch-to-scale-polyline' ALMOST has the functionality I'm looking for, but I'm not trying to split out an individual segment of the polyline. Instead, I'd like the ability to break a long polyline into two markups, keeping all control points intact on either side of the break. Autocad had a similar function with polylines, if you're looking for a comparative feature.