I can't speak to Gleam, but for Elixir I just used Burrito to create a single executable: https://github.com/burrito-elixir/burrito I think it works for just Erlang too.

I haven't used it, but from the docs, I don't see why this wouldn't work for any language that compiles to beam files. You might need to adjust the build setup a bit.

Personally, I think I'd prefer something that worked without unpacking, but I don't actually need something like this, so my preferences aren't super important :D