In the user manual section on the ellipse assistant, it says
If you press the Shift key while holding the first two handles, they will snap to perfectly horizontal or vertical lines. Press the Shift key while holding the third handle, and it’ll snap to a perfect circle.
But when I hold Shift and click, it doesn’t seem to do anything. In fact, it won’t even let me place a point when I’m holding Shift. Is there something I might be doing wrong?