The solution points to how, it appears, the book panel export is functioning: each file exports a set of tags referenced to itself; file01 adds a "1" to its tags, and so forth. What I was able to do was use a file referencing all of the tags in the style suite in two ways:
- first, I exported to an epub the single file, creating a fairly clean CSS, which I then extracted and renamed;
- then, making certain that file was the "source" file in the book panel, I mapped for export all of the tags, being careful to be certain each tag/class combo was same as in renamed clean CSS;
- I synchronized the whole shebang;
- I exported to epub, adding my clean CSS as an external style sheet, selecting only "include embeddable fonts".