So im playing with lazycam / mach 3, trying to cut one of the triceratops. Dxf file i got from here. Loading the gcode to mach 3, some parts are outlined in blue, these parts cut fine in one z motion.
Other parts are in red and the machine takes small bites in the small arcs. Ive noticed that as it starts cutting the red lines, it seems the z axis is not all the way to z0 at the start of the cut so its leaving thin tabs.
These do seem to keep the part from popping up and getting blasted out by the spindle.