So instead of auto-completing bits of LLM-generated code into the codebase, you preprocess it in. I can imagine a lot of devs won't like the ergonomics of that, but I like the idea that you can keep both original .glp and generated source files in version control.

I'd strongly recommend going over the README by hand. What you currently have is redundant and disorganized, and header sizes/depths don't make a lot of sense. The "manual build" instructions should also describe the dependencies that the install script is setting up.