If you use a 2D contour
select a point for the descend/retract position and then select the contour
so in the goemetry you have point, contour, next point, next contour, etc
in the lead in/out ---use entry point & exit point
you can do this for many situations where you may need the tool to start outside the stock boundary or in a pre-drilled hole, sometimes works with pocketing too,