To simplify my earlier post: Set inside only Machining diameter to ‘cut diameter - tool diameter’. Remove the end of the finishing block/program clearance plane move and all lines up to the second to last clearance plane move. While they won’t do serious damage, they are out of bounds and the Z0 DOC can leave a very subtle mark on the uncut surface.
Example G-code preview shows the fully cut bowl (green) and what’s left (red) after the second to last clearance plane move.
Solid of Revolution (SOR) always has a center of the project origin and the easiest way to do any two sided project is to use four locating holes/dowels an equal X,Y distance from the project origin. A drawing with the holes and a part perimeter circle is needed to drill the holes and cut a tabbed perimeter part path. One flippable (in Estlcam) or separate top/bottom section drawings are needed to generate the SOR G-code.
Without grid holes/vacuum, the easiest way is to drill holes in the spoilboard and then in the top of the mounted material, cut the inside of the bowl, insert dowels, flip and remount the material, Depth limit the bottom SOR cut to leave a bit of material and finish the cut with a tabbed Part path. See EstlCAM 2 sided cuts - #16 by dalrun for a 2x 3D example.
A number of v11 features were dropped, e.g. SOR, or significantly changed in v12.