Selection and canvas bounds?

[Ottia Tuota]

But the idea is that the user would choose which part of the path should be manipulated and which part should be kept as it is. That information should be passed to the plugin, and I wanted to use a selection for that purpose. But if the selection is always bounded by the canvas, all out-of-canvas anchors are out of reach. And the user may want some of those out-of-canvas anchors to be manipulated and some others not.