in my opinion If the wall flip is drilled into the wall as an external wallhole in two different walls Shouldn't there be a way to make the materials work together? Because it is a form that exists in the same position on a plane or cross section!.
The concept of wall flip does not exist in revit or autocad architecture, so I think there must be a solution.
If you say that you have to make a new shape with wallhole status 2, there is nothing more you can say. ^^