TeX4ht could be an alternative for what I'd like to achieve. Speaking as one of the (sort of) maintainers of tex4ht ... sure, give it a try, I'll be curious what you think, but I doubt it'd be easy to make use of it. tex4ht has lots of complications of its own. It can, in general, output mathml, but that support has not significantly changed since the original author (Eitan Gurari) died in 2009.
latex2html, by the way, is even more problematic (and, so far as I've seen in recent years, even less maintained). MathML support because of security concerns How can mathml be more of a security concern than a huge javascript program?! Oh well, no need to answer :). And Chrome's decisions re compatibility are inscrutable anyway, similar to luatex's :). I am not a fan of MathJax. Fair enough, no argument here :). Best, Karl