Ah, yes the pocketing operation includes the radius of the cutter for the purpose of cutting out the pocket contours at the specified contouring Z plane - so the user doesn't need to include it in the offset. In other words, an offset of zero will cut out a pocket that matches the canvas as contoured at the Contour Z plane.
Also, if you weren't already aware, you can enter math expressions into parameter text-edit boxes, such as:
tan(20/2)*0.35
...and PixelCNC will evaluate the expression and output the result :)
- Charlie