Jack
What I showed was done using a custom 'corner piece' object. Place it at each corner and run your wall to it. You would, of course, have to create a separate piece for each different wall type.
Creating the object involves using the radius piece that a fillet creates, using solid operations on two short sections of profiled walls, saving as on object, cleaning up the 2d view, and a couple of tricks to make the 2d view compatible with your standard 2d view options. Call me if you want to be walked through the process.
A comment: it would be easier to make the model display as you want if you separated the wall into stories (e.g.: the first floor portion and the parapet portion); the parapet could be done with a radius since you probably won't be cutting a floor plan through it and the first story could be done using composites.
I can send a copy of the Archicad file that I used.
Jim
James C Lewis
AC 24 (Full)
Mac Pro (Late 2013) OS 10.13.5