And if you have any other global state you want to pass around, you can pull off a clever trick by passing it around as a binary and then unpacking it as needed within caller processes.

AFAIK this trick is why BEAM files use an IFF-derived format (easy to parse individual chunks out at runtime), and why erlang:module_info/{1,2} are the way they are: working with module metadata literally just means asking the code-server process for the (shared refcounted) module binary, and then parsing it yourself.