Yes. It produces an extremely detailed (3rd level) ToC. If I remove it, I get a ToC only half as long.
One of the eccentricities of this document is that the ToC is just as, if not more important than, the text. Keeping it produces both a shorter ToC and the need to plow through the document again and implement your suggestions concerning italicized text. It’s easier to remove the crosshatches in Sigil than to re-do all the italicizations and make sure that they work–there are two struck-out sentences as well that I am afraid to address. The issue with italicization–and I very much appreciate your in-depth analysis–is that in this type of legal writing, they convey semantic meaning. They are not used for emphasis–the italicized sentences carry no more weight than the non-italicized, but they are new, and this has be conveyed somehow. Emphasis is a trap: just because a sentence/paragraph/page is new doesn’t mean that it has more gravitas than an old sentence. Additionally, different regulations that implement these laws are included here, which is not the norm for statutory books which print laws discretely. How to make them stand out? One way might be to use different fonts. Ultimately I decided on italics for these as well. I have seen other legal publisher relegate these to footnotes or omit them altogether. Footnotes are troublesome in the ePub world: some readers convert them to end notes, and while clicking on them is supposed to be easy, it is often difficult to navigate back to where you left off in the text. The legal world still hasn’t figured out what to do with the loss of page numbers, this is probably the reason why ePub’s have not overtaken pdf’s: you just can’t cite to an ePub like you can to a pdf.