Every SVG element and attribute pair and every keyword went through both tools, tens of thousands of cases: same findings, two documented gaps aside. Two false reports are gone, e.g. fill-rule with spaces around it.

Every SVG element and attribute pair and every keyword went through both tools, tens of thousands of cases: same findings, two documented gaps aside. Two false reports are gone, e.g. fill-rule with spaces around it.
Its CSS parser, styloria 0.12, follows the CSS Syntax draft W3C published on 1 Oct. Two CSS false positives are gone, and the same book now gives the same report on every run.
On my 544-book shelf: 18 s for all, epubcheck ~18 min.
Second: calibre's Edit Book. Same validator, results in a dockable panel, click a row to land on the line.
github.com/veripublica/epubveri-plugins/releases/tag/calibre-v0.4.4