Tell us what you would need described in a tutorial to be productive, as well as your background with the technologies involved (TeX/LaTeX, perl, XML, XSLT, HTML). Probably best as a new issue:
ar5iv tracks the arXiv collection with a one month lag. Exactly as to signal that this is not the "official" arXiv rendering. It is also a showcase predating the arXiv /html/ route, but largely using the same technology. Nowadays maintained by the same people (hi!)
There used to be another showcase, called arxiv-vanity. They captured what happened pretty well with their farewell post on their homepage:
You can help make LaTeXML better, or you can simply report issues when you spot them during reading. Some we have collected automatically (any errors and missing packages), but others we can't - wrong colors, broken aspect ratios of figures, weirdly layed out author lists, etc.
As a very brief update - we are pending a larger update.
You will spot many (many) issues with our current coverage and fidelity of the paper rendering. When they jump at you, please report them to us. All reports from the last 2 years have landed on github. We have made a bit of progress since, but there are (a lot of) more low-hanging fruit to pick.
The main bottleneck at the moment is developer time. And the main vehicle for improvements on the LaTeX side of things continues to be LaTeXML. Happy to field any questions.
Just passing by to mention that if you get excited about seeing your upgrades in arXiv itself, we can talk about contributing them to the arXiv HTML pages.
But seeing your plans for Science Stack, all the best with the endeavour!
And I am curious to know if arXiv:2105.10386 works well.
https://github.com/brucemiller/LaTeXML/issues
It's a pretty deep rabbit hole, but I wholeheartedly agree most standard package support incantations should be easy and few to use.