tempfs Hi! sorry for the late reply.
Unfortunately no, unless you offset the middle point slightly (by changing the grid snapping paramters).
The way it works is that all points are used to generate a new shape that is getting rid of the, and that shape is then contracted/expanded to build the wall thickness.
PathOffsetter offsetter = new PathOffsetter();
offsetter.Offset(ref output3, 0);
offsetter.Offset(ref output2, -AppController.Instance.interiorWallThickness);