Thanks for the reply.
- I'm using the KoboTouchExtended driver, so I'm also getting the kepub over on the Forma. But, I've tried sending the book over to the Forma without that and saw the same lack of TOC in the epub as well as the kepub.
- Looking at the pre-conversion file in Calibre's viewer also shows no TOC. I wonder if the version downloaded to my computer from Kobo is different from the version synced to the Forma from Kobo. Is there some way to side-load the synced version on the Forma to Calibre?
- Under Preferences > Common Options > Table of Contents, everything's blank (default, I think). But, I've tried turning on "Force Use..." and "Detect and Markup Unformatted Chapter Headings and Subheading" under Heuristic Processing, but still end up with nothing but "Start" in the TOC. Also, I noticed that in the converted book, there's no time to the end of chapter. So, it looks like it's not seeing chapters at all. The only way I get anything showing up while editing the TOC manually is with the "Generate ToC from Files" option. I know nothing about that, so I'm going to have to research some more.
- I'm doing the conversion because that's what I've always done

. But, really, it's primarily to increase the font size throughout the book. Under Common Options > Look & Feel > Fonts, I've increase the sizes there, under Heuristic Processing, I've enabled it to remove unnecessary hyphens, and under Structure Detection, I'm removing the first image and inserting my metadata at the start of the book (basically, to see my review that I keep in Calibre).
Thanks, again. At least I now have a starting place to see if I can figure anything out.