Is there a reason for RMX Harmonizer producing unharmonious results with open contours? Here’s a before and after showing the strange results at open ends.
The problem is that the first node is aligned to the last node of the path, because it is marked as a smooth curve point. Glyphs does not display the usual green/blue because it is an open path. RMX Harmonizer does not differentiate between open and closed paths.
Workaround: select the point and press Return. This switches it to a corner point. Then run Harmonizer again.