Well, I managed to add in backwards links from the footnotes to the text using regular expressions. Nifty. Thanks for the warning to include those.
But now I have a new question. There are links in the text simply to other places in the text that are not footnotes. For example, "See the poem by so and so." I can't possibly have backlinks from those. How does a reading device that does not have a back button deal with that?
Honestly, I couldn't have imagined the navigation on the Kindle being any more difficult than it is. But not having a Back button. That just doesn't make sense.
@HaryT What is PG, if you don't mind?
Thanks for all the help.