Is there a functional limit on how large a course can be? Are there any known issues with running very large courses?
On TestTrack, we limit the size of courses simply because of
bandwidth/upload concerns, but as Engine licensors, you have the right
to do what you like in that regard. Ultimately, the limitations in
place here are not related to SCORM at all. The things you need to be
thinking about are bandwidth, download/upload times, storage space... I
don't have much expertise for you on these items, other than to say
that SCORM will largely stay out of the way.
It is possible that you would have memory issues with extracting a massive zip file with the course or something along those lines If you get to the point, though, where you're running into that problem, I'm going to be thinking, "If your server can't handle it, what's your user's browser expected to do with it?"