No, I don't think anyone's working on this. It is also very unclear if it is really worth the effort (for a good overview see https://lwn.net/Articles/615235/ from Stefan Monnier, Emacs' ex-maintainer). For speeding up Emacs Lisp, I think the current work done by Andrea Corallo using libgccjit is more promising. Another big boost would probably be to replace the current regex engine with something better.