Window Wall Closure - Skin turn - 3d / Sections reveal

[CareA]

Hello,

I have a wall that is a composite made of interior plaster, masonry wall, 15 cm thermal insulation, and exterior plaster. I inserted a window frame where the opening is 2 cm larger than the frame itself. The idea is to close the frame on the outside with a 3 cm thermal insulation layer and exterior plaster. Everything looks good in plan view so far. The problem is that in 3D, the area where the thermal insulation wraps around is actually turning into masonry, which will result in incorrect quantity calculations and also in a section view it will appear entirely as masonry. How can I make the wrapping thermal insulation actually penetrate through the masonry? If I set the thermal insulation to be viewed as plaster, then I can’t set the thickness of the wrapping insulation. 
Thank you.

Operating system used: Windows 11

[Lingwisyer]

The wall closure setting is purely a 2D representation... There is a wish for this around somewhere... In the mean time, you can place a composite or complex beam across your sections to get the required detail. 

I started making my own object that does this, but I seem to have broken something in it before I put it on hold...

Ling.