I have the Best Practices (Ss3) PDF but it does not address this topic deeply enough. We do not cut cross Sections that often and it seems like it takes a number of attempts before the results are acceptable.
I'd prefer a standard operating procedure as to what references to attach and where to attach them and what live nesting (if any) to use where. I would also prefer to avoid having redundant attachments as most users, including myself, find the " " " settings in the reference file dialog box of redundant reference files not as intuitive as Bentley seems to think they are.
For example, yesterday, I created a file for cutting cross Section in. Started with 2D - attached my alignment and corridor file, one of which brought along the existing ground file. When I viewed dynamic sections, everything appeared as expected. But when I ran the Create Cross Sections tool, the model in created displayed my sections, my sheet reference files, but the existing ground was missing.After trying various options, I finally decided to directly attach the 3D model of the exiting ground to the 3D model created by Open Roads during the Dynamic Cross Section command. Only then did my cut cross sections result in the existing ground being included in the sections.
Yeah cross section's have a different workflow. What I have found that works every time is to attach the alignment file, attach the terrain. Make the terrain active. Open 3D model and attach the 3D model of the corridor. Open 2D model and cut cross sections. No nesting on any of the files.