This is really cool! We had a thread previously discussing the need of real scripting language: Kakoune needs a real scripting language and in it there was several lua examples you may find interesting.
I’ve defined this abomination https://github.com/andreyorst/dotfiles/blob/master/.config/kak/defperl.kak but never actually used it, because I mostly fine with shell script. Some of my plugins do use Perl, but I just call functions from files directly via shell. But your solution seems like a quite nice library