Double off-centre vertices
In the upper left quadrant, two of the intersecting white arcs are of opposite curvature, so they intersect twice.
Which is the true vertex will have to be worked out. In addition, I marked the intersection of these two with a
white arc. I discovered in the examples of "others" that single white lines/arcs are to be ignored, but what if
they intersect other arc/lines off-centre that look as if they might be real?