When I cut B splines, I only draw the geometry for the center-line of the custom cutter. I create one toolpath operation at an index angle of zero. Then I transform that toolpath 180 degrees. These 2 operations will be my first toolpath with a program stop so that I can measure and adjust the offset measured across pins. Then I will cut the rest of the splines using transform toolpath. I have cut spines in Inconel Aerospace components using this method. If you have an odd number of spines, you will have to cut the first spline at zero and then two spines on the opposite side of the shaft so that you can measure across three pins. The deburr toolpath does a great job of deburring splines. In the photo below, that is an .008 edge break done with a ball end mill. Inco 718

I ran out of space here so I uploaded them to an image hosting place https://postimg.cc/gallery/9M2MTn4 So you basically have to make a macro called MANUAL_ENTRY with the custom gcode dialog. There is one box to add a new line up at the top and at the bottom there's a box that says add codes. So insert like 10 lines and copy the example