There's also the book "Creating Solid APIs with Lua" by Tyler Neylon [1,2] which seems to be quite specifically addressing this idea of embedding lua in something so as to implement highly-movable application logic in lua rather than the something you started out with.

[1] https://www.oreilly.com/library/view/creating-solid-apis/978...

[2] https://github.com/tylerneylon/APIsWithLua