Like JulianTodd said and Sliptonic seconded: we could use an energy beam approach for cutting if not milling. This approach could make freecad more amiable to those of us using laser, water jet...etc. They generally place more emphasis on speed than position. They generally don't perform retracts willy nilly (rather shut the jet or the laser for rapids). They provide covenience in start-point selection and lead-in/lead-out.
In some cases (laser scanning) they allow overshooting the milling layer beyond the contour, shutting the laser when outside the pocket, and turning it on inside. An approach called "sky-writing". Also widely used for engraving. There's a GRBL scanner g-code generator that's open source but very barebones
http://lasergrbl.com/ the developer
https://github.com/arkypita/LaserGRBL seems quite active. Perhaps already a contributor to freeCAD? Or a future one?
There's also a need to be able to round corners (specifically for zig zags) to keep the head moving smoothly (again, feedrate is more important with energy beams to smoothly distribute their energy output on the surface of a cut or pocket).
Anyway if someone wants to tackle that, I'm happy to help consult on the topic.