You can access lines drawn by Revit trough API - see https://www.revitapidocs.com/2020/d8a55a5b-2a69-d5ab-3e1f-6cf1ee43c8ec.htm. There’s no need to create slices.
You can divide Nurbs:
https://dictionary.dynamobim.com/#/Geometry/Curve/Action/PointAtParameter