How to undo while drawing sketches in GVH

I was wondering if it is possible to undo a drawing action in GVH, and more specifically, remove the last vertex when drawing a polyline or polygon.

I've seen this discussion, but it's a couple of years old, and it's unclear what the status is.

The administrator and developer guide contains keyboard shortcuts that could help somewhat. I could for instance just finish the sketch, go into edit mode, press v until I find the vertex I want to delete, and then press d.

This is obviously a bit cumbersome, so I'd like to know if there is an easier way to either undo (by keyboard or mouse), or remove vertices by using the mouse.