Hey! I'm not sure if this is exactly what your are looking for, but I use Inkscape for all my vector graphics needs. It does have a trace function to help convert raster images into vector, which might help. And you can do CTRL+L to simplify it. I have used it for creating SVGs for a vynal cutter, which might be similar to what you are doing? I've used it on Linux, Mac and Windows without much issue.. but there might be a little learning curve.
I definitely remember seeing someone on YouTube sewing after using some built-in Inkscape extension to optimize route and color switches. It was pretty surprising to find such tutorials.