All these information can be extracted from the Wall properties and calculated with "Properties & Expressions".
I didn't try it, but I am sure there is a Wall_Radius and a Wall_Angle. Once you have them, its "Just do the math"
i.e.: Create a new property called "Arc Tangent" > Insert in it an expression that calculates the tangent using the Wall_Arc and Wall_Radius > Associate this property to the "fake wall" > Create a label that extract this property > Associate it to the wall.
Then do the same to the other properties.
Hope that helps.