Where?
https://sigil-ebook.com/get/ →
https://github.com/Sigil-Ebook/Sigil/releases
Another couple of questions while I experiment:
1. In the Search & replace, although the regexes work fine when testing with the wizard, the strings still end up in the EPUB. Any idea why?
2. Is there a way to tell Calibre to ignore such and such pages in the input file, such as those that contain the ToC or tables, since I know they'll turn into garbage anyway? I might try and replace the tables later in the EPUB as PNG instead.