Border Spline Version: 1.0
Date Updated: 01/26/2018
The free scripted shape plugin will generate a spline along all the borders of all the editable poly objects assigned to it. For non-editable poly objects, apply an Edit Poly or Poly Select Modifier to use with this shape plugin.
Thanks to Vojtech Cada for demonstrating some of the .NET classes needed to work with simplespline in his plugins.
3ds Max 2016 SP2+