Hi, I may have found an issue which should be fixed.

When I used CGS.Substruct() for a couple of times, I found Node.polygons.Count had rapidly increased. This was actually caused by

List list = this.polygons;

in CGS/Classes/Node.cs line 171. Since when list changes, this.polygons also changes, the code above should be like

List list = new List(this.polygons);

Sorry if this is just my misunderstanding.