I’ve had bad luck with long posts, so i’m going to split this into parts.
Included Postprocessors are saved in the FreeCAD.Mod.Path.Pathscripts.Post by default:the grbl post seems to generate decent output, but i'm wary.
the FreeCAD Path (CAM) workbench itself is pretty bomb. they have 2D adaptive, and 3d contour just around the corner. it is ready to roll for 2.5D, and i found it much more straightforward than fusion.
using the grbl post i get decent looking repetier preview
i did an air cut and it behaved basically correctly. but i can’t tell what the feeds are doing, and there was never a way to specify my rapids.
i’m asking on the freecad forum at the same time…and if no one can talk me out of it i might cut something