Does anyone know how to open surface and polysurface correctly?

Good Morning,
Does anyone know of any really efficient way to open (plan), superface and polysurface?
Squish, does not maintain the correct perimeter.
Smash, besides not maintaining the perimeter, deforms the planning.
Plugin, or correct way to do it in Rhino?

Hi -

Surfaces with compound curvature cannot be unrolled exactly and some stretching/compression will always occur. A 3rd party plug-in that is sometimes mentioned is “ExactFlat”.
-wim

Thank you very much, I will research this.