The Error Margin parameter controls when the shape is terminated. If it is low, points in the direction of sharper turns in the original path can be deemed too far away to be considered a valid continuation. If it is high, narrow parts of the original path might be sampled, thus skipping some of these parts completely. If very high, the whole path might be sampled multiple times:

The parts of the path where this happen depend on the starting direction — you can usually tweak the Seed to avoid early trace termination. The bigger the radius, the bigger gaps can be skipped with a high error margin:

Installation: Copy the .ms file to your scripts\startup folder or run as a script if you want to try it out first. The object primitive will be available under Geometry > Examples in the Create panel.