I am afraid that I do not understand why -- other than for printing purposes -- a single large PDF is more useful than the exact same information available from within FrameMaker as a topic-based online help (where the search is much more effective than Acrobat's Find function).
BTW, anyone with Acrobat can convert a web help system into a single PDF (through File > Create PDF > From Web Page, pointing to the help main menu page). Shlomo Perets MicroType, http://www.microtype.com Training, consulting & add-ons: FrameMaker, Structured FM and Acrobat