In fairness, luaffifb seems to give the same feature. I think the main argument against Lua + luaffifb is that it might require an external dependency: luarock

In fairness, luaffifb seems to give the same feature. I think the main argument against Lua + luaffifb is that it might require an external dependency: luarocks. Whereas if someone were to theoretically provide Lua integration with emacs, it might be a good idea to offer the ffi library as a baseline feature. This is a weak argument, because it should be possible to embed luaffifb plus Lua inside of a linked library, with no need to depend on luarocks. It's probably best to explore both options.