bounding box line thickness is confusing
The code that draws the bounding box is a stroke
addon to the clip path, which is elegant. The clip path is a line in the math sense. The same path used for clipping, when stroke
d has a finite width, defaulting to 1 point, but the outer half of that width is outside the clip path and only the inner half is printed, resulting in a 0.5 pt line, contrary to what some readers might expect.
A 0.5 pt line is actually a great choice, so I'm not suggesting changing this. It would simply be nice to be able to understand this better from reading the sources, as it took me a while to figure out what was going on, prompted by #3, and there's some chance another human will try to figure this out.