Extract boundary of ramp

Revit didn’t like my ramp so I want to take the boundary that I sketched into GH, divide the curve, remap the Z’s correctly then loft/patch to create a direct shape.

Is there a component that lets me extract the boundary of an element? Projecting the actual ramp geometry isn’t good because revit warps it to create the model.

I am also able to grab the boundary by exporting the linework as a DWG.