Here is one that we’ve written that will make some significant “first pass” optimization of path order: https://github.com/evil-mad/axidraw/issues/4#issuecomment-272845935
(We’re actively working on the next revision of this, and hope to release it shortly.)
Depending on the format of the output SVG from your program, you may need to ungroup and/or break paths apart before using our extension for maximum benefit.
