Concerning Lua: there are approaches for years to add static typing to Lua, but from my point of view (as a language developer) none was really good when compatibility with Lua on language level (such as TypeScript vs. JavaScript) is a goal. With my own languages I only reused the engine without Lua compatibility, and the resulting language is much better suited for large-scale software engineering. But the approach based on LuaJIT turned out to be too brittle, so I switched to the CLI Mono engine, which is much faster (factor two) and much more stable.

> Once you're able to typeset something, we'd gladly accept a progress report at TUGboat

Currently I try to find out whether a Pascal based typesetting language with static typing would be worthwhile or not. Otherwise I will likely implement something like Typst (the latter is actually the reason I started this journey because it is for one part a much better language than TeX, but for the other part the typesetting quality is much worse, and this doesn't seem to change for years when looking at the roadmap).