LuaJIT is missing bignums, ints that aren’t floats, bit operations, and native utf8 handling, but it can pretty easily be extended with libraries, ffi and metatabling. (I actually made a working bignum library that integrates with gmp, but it has a memory leak somewhere and it’s a rabbit hole/bikeshedding project at this point…)
LLM assistance helps hugely and I really like YueScript’s syntax additions. You can point any LLM at a syntax describing webpage and it will pretty much write that language for you…