Hi Max,

re: Here's a simple example of overlapping lines.

So unfortunately that's the expected result currently - dealing with curves occluding other curves along silhouettes is a generally difficult area to handle.

There is some silhouette curve duplication prevention in the hidden line engine but currently it's limited to cases where the curve is completely covered up by another curve - that catches cases like a box or extrusion viewed from the extrusion direction, but won't catch cases with staggered partially hidden curves like you have here.

Currently there is somewhat more of a focus in the engine on trying not to have missing areas rather than trying very hard to remove all overlapping duplicated areas like you have here.

Possibly it's something that can be improved in the future but it will likely take quite a bit of work.

- Michael