[0]https://www.print-css.rocks/tools
I mentioned https://polytype.dev/ in the end of the post, which has pages.js included.
Is not that hard to simulate pagination with JavaScript, the deal breaker for me is still line breaking and also mixed languages typesetting nuances.
You also didn't mention the new (Chrome only) CSS text-wrap: pretty
https://developer.chrome.com/blog/css-text-wrap-pretty
https://docs.google.com/document/d/1jJFD8nAUuiUX6ArFZQqQo8yT...
https://chromestatus.com/feature/5145771917180928
[0]https://www.print-css.rocks/tools