I agree with this. While rounding errors might cause strange behavior in some cases, I'm fairly certain the vast majority of these "impossible-to-draw" arcs are going to be generated by our internal library livarot incorrectly writing arcs. Which means that the endpoints are going to be exactly the same, not simply within rounding error.

or there should be a way to set this threshold (in
Inkscape, it should be dependent on the numeric precision of XML
output).