On my current project I modeled some kind of wood deck, each piece of wood
I modeled with slab tool (over 1k pieces) ...it looks really cool but actually pointless...
I had similar situation this summer and figure out that ArchiCAD is not
built for this kind of task...it just cannot handle all that polygons...
it slows down very much without using all hardware capabilities, I was carefully watching memory and cpu usage during 3d or section generation...
it was less than 20%...
so real question is do you really need all that staff in 3D?
btw GREAT looking model...beautiful...congrats