@siracusa - Two Shapes!! One “nested” inside/below the other… Top has no stroke/fill…Bottom has DOUBLE thickness you want w/line still centered on path. When you drop the “bottom” ellipse onto the top one, it gets masked, and so it gets hidden. Just Change the inner shape, leaving top shape alone, and you can have partial ovals showing, (D). — Just drop the stroked shape on the non-stroked shape to mask. Done. You’ll see them all in the Layer panel.
