Well, that hurt. But it's fixed.
I tried/verified all the above except the Cloud Cleaner. At that point, I had a thought and ran with it...and that is what got me there. I can't say for sure if it was the document itself or something about the underlying Presets file(s), but, should anyone have this issue, and have no luck after trying some/all of the above steps, here is what I did to fix it:
- I created a new ID document, same Document setup specs as the one I was working on.
- I copied and pasted each page's content from the working document into the new document. (Naturally, there were some missing links and other anomalies, but I wasn't looking to create a fully functioning new version of the working document because I was focusing on the Presets function.)
- I saved the new document and closed the working document.
- In the new document, I opened the 'Export HTML 5 with in5' menu item.
- I set all of the same preferences I had used in the working document
- I clicked 'Presets...'
- Clicked 'New...'
- Entered 'eLF' and 'Save Preset'
- Joy. It took.
As I alluded, I'm not sure what actually caused this but the above, for me, resolved it.