Hi wim, the only way to do it currently is the way that you described with adding in a new corner point and deleting the old smooth point.

It's on my list to add some easier way of switching the types of existing points.

But I'm not sure if that will help you with the "curve goes berzerk" problem, most likely an easier switching method will still have the same behavior that you're seeing now.

Can you post an example that shows what you are describing there?

- Michael