I'm hopeful that it will work without needing to save the site as a library part. Since I posted yesterday I have done some move investigating.
I selected all the roads in ArchiCAD and changed their IFC classification from "automatic" to "wall". Now they show up correctly in the IFC model, SEO's and all.
I also have about 20 identical walls, with identical SEO's, that I am using as property lines so I can see the property boundary in 3D. About half of these translated OK, the other half didn't. I have called tech support and they are working on it. It seems to me that if some walls work OK, they all should be able to.
Still haven't heard anything about what is a "site object" an how to define one.
I will post again after I hear back from tech support.
R Muller
AC 26 USA (20+ years on ArchiCAD)
MBP 64GB Apple M1 Max OS 12.1 Monterey