In this figure, in order to drag the vertical line from side to side, I have to start clicking off the vertical line. This is unintuitive: I'd expect to be able to click on the object to be dragged and drag it.
Jupp, they seem to be in the wrong z order. Tracking in #29, but leaving this open for now as a reminder that all diagrams with handles have this issue. :-)
In this figure, in order to drag the vertical line from side to side, I have to start clicking off the vertical line. This is unintuitive: I'd expect to be able to click on the object to be dragged and drag it.