Hello! I’ve been meaning to flag this for a while. It seems Harmoniser isn’t really intended for open paths? In some designs I use a single stroke as the thinnest master, so that I can generate other masters by applying a stroke and then adjusting. But before I apply the stroke I sometimes want to check my curves are nice. Unfortunately, end points (but not start points) are always moved into a completely different place. Of course I can undo, deselect those points and try again, but I thought the behaviour should be noted.
The top pic: the last point is defined as smooth. Select it, press return and try again. I do think harmonizer should always treat open path ends as corners.
Bottom: I believe this has to do with Harmonizer trying to keep the overall area the same. Since it has a wider curve (=more area) on the left, it has to compensate on the right.