Hi Michael - we also use Purple Pen for course planning and then export each course to a GPX file from Purple Pen. One of our club members has written a couple of routines available here -
https://tools.widmann.ca/ - which convert the GPX file into a KML file suitable for upload to MapRunF. Then the controls are numbered 1,2,3, etc. rather than using the control numbers. His routine for a score course leaves the control numbers alone as that is more common with a score course.