Still messing with this.

Just imported the same file - a single 19mm circle, drawn in my CAD program, into SheetCam and Aspire. Used the same tool, same profile type, single pass cut, outside edge.

Sheet cam seems to make the hole in one go...
N0110 S24000 M03
N0120 G00 X9.5000 Y-1.0000
N0130 Z1.0000
N0140 G01 Z0.000 F250.0
N0150 G02 X17.2584 Y2.4249 Z-3.0000 I0.0000 J10.5000
N0160 X17.2584 Y2.4249 I-7.7584 J7.0751 F487.0
N0170 G00 Z20.0000
N0180 X0.0000 Y0.0000
N0190 M09 (Coolant off)
N0200 M05

And Aspire seems to do a circle in four arcs?...
N130 S24000 M03
N140 (Toolpath:- Profile 1)
N150 ()
N160 G94
N170 X0.000 Y0.000 F377.0
N180 G00 X0.000 Y10.490 Z20.000
N190 G00 X0.000 Y10.490 Z2.000
N200 G01 X0.000 Y10.490 Z-5.100 F377.0
N210 G02 X10.490 Y0.000 I0.000 J-10.490
N220 G02 X0.000 Y-10.490 I-10.490 J0.000
N230 G02 X-10.490 Y0.000 I0.000 J10.490
N240 G02 X0.000 Y10.490 I10.490 J0.000
N250 G00 X0.000 Y10.490 Z20.000
N260 G00 Z20.000
N270 G00 X0.000 Y0.000
N280 M05

Any further ideas?

The posts for aspire all have ARCS in the names, using a non ARC post generates thousands of very short lines for a circle.