To bring this thread back to the original purpose: It doesn't seem like there are any objections to having this package in GNU ELPA, in its current form. I'd like to resolve this long-running discussion by committing the first version. I believe I have commit access, so if no one does object, I can add this to GNU ELPA myself. I'll do so on Friday (September 15th), unless someone wants me to hold off.
Another question is whether this should be one package or many. The many-package option would have the llm and llm-fake package in the main llm package, with a package for all llm clients, such as llm-openai and llm-vertex (which are the two options I have now). If someone has an opinion on this, please let me know.