Approximately flat curves or parts of curves are aliased

A very visible aliasing effect comes in places where a curve or a part of a curve is approximately flat, and the containing triangle is very thin. The anti-aliasing strategy does not take any effect in these places, most likely due to the fact that the fragments are shared with the internal fill shader and there is no overlap, so the rasterizer picks the fill for these. Thus this is related to the issue of the gaps between curves.

One pragmatic possibility might be to detect flat parts and try to replace them with actual line segments instead, decreasing the fidelity of the design, but maybe not at any real visible cost.

But we should probably see how the gap pixel anti-aliasing pans out first.