Unroll Brep and Unjoin Edges

I'm trying to unroll breps with unjoined edges so i can control how they unroll.

Basically I have a whole lot of angled boxes (acoustic diffusers a la Melbourne Recital Centre salon) without a bottom face, and I want the vertical edges to tear, leaving the top connected to the sides when they unroll. 

 unjoinEdges doesn't seem to be implemented in the rhinoscriptyntax. Is there a way of doing this in python with RhinoCommon methods? Or can the '-_UnjoinEdge' command be used in the python component? I've tried splitting with the edge curves to no avail. 

I can achieve what I want by baking, then unjoining the edges manually, however I'd much prefer if I could find a way to keep it linked. 

Thanks in advance for your help. I have attached .GH, .3dm and images below.

best, 

Dharman

This is what i get:

or this: