Oh, wow. That's fantastic!

> There is a Typst package called MiTeX that supports at least some basic TeX input.

I can see that being useful for lots of people, but, as a migration path (as I understood your parent https://news.ycombinator.com/item?id=43106837 to suggest), I don't think it would work. I've worked with TeX for almost 30 years and used vim for about 20 years, and suspect that "supports … some basic TeX" is likely to have the same effect for me as something that emulates vim does on a master-level vimmer—falling into the uncanny valley that's somehow worse than a totally different thing.