Event for Scaling Interaction to modify Bounds of MarkupsPlaneNode?


I’ve been experimenting with vtkMRMLMarkupsPlaneNode.PointModifiedEvent to control the dimensions of another object, in this case an elliptical cylinder.
The idea is to put the plane of the MarkupsPlane along the major radius vector of the elliptical cross-section of the elliptical cylinder. By dragging the Interaction handles for Scaling of the MarkupsPlane, I can control the major radius of the ellipse and the length of the cylinder.

When I try to use the vtkMRMLMarkupsPlaneNode.PointModifiedEvent to fire an event after dragging the Scaling interaction handles with the mouse, I don’t get an event. As the name suggests, the PointModifiedEvent only fires when I drag the rotation wheel or the center control point to translate.

These two events are still parts of the Interaction handle, yet they trigger PointModifiedEvent. Why does the Scaling handle to modify the bounds of the plane not fire an event?

Is there a workaround to fire an event in this case?

Btw, I guess I need to prevent an infinite event loop, so I first remove the particular callback before I modify the bounds from that callback function. I’ve had Slicer crash sometimes when I don’t get that done right.