I've watched a couple of episodes and went started my own. I learned a bit of arm64 assembly, and now I have both an interpreter and a compiler to M1 binaries. Very fun experience.
One day I'll slap a F#/OCaml'esque syntax on top of it with typed functions, structs, interfaces and see if it works.
At their core(it seems to me), concatenative languages are about function (words) composition.
So, instead if having "words", I would make them functions, with typed arguments, and simple argument matching (no more dups and swaps). This would probably make the language less flexible, but will make it more readable.
Anyway, FORTH is nice.