As always, thanks for the excellent information/clarification, Jeff.
While trailing your lead with this issue, it's at least good to know that I am on the right track. I know that SSM hasn't been improved for many years, but only having COM access is also pretty disappointing... Yet explains why FDOT spent thousands of taxpayer dollars to build a Sheet Set Organizer app that sits on top of multiple Sheet Sets, rather than simply add the nested sheets in appropriate sub-sets (they're Microstation/VBA developers).
This issue aside, I'm less than impressed with C3D's PPT in general.