It would be great if interactions only became active when you were inside the shape/path you have set it on. Currently, it becomes active when you enter the bounding box of that shape or path, this makes it difficult to prototype interactions for non-rectangular elements that are located close to one another. It can make the target area of a shape to be clicked on or hovered over almost non-existent or overridden by another element in the frame.
Having this working correctly would make a massive difference to creating effective and interesting prototypes.