since the foundation models are usually a few years out of date
is there any tool for adding up to date verions of the source / documentation for frameworks / libraries like nextjs and tailwind?
That's a really great idea, you can do "data analysis" with newer versions of ChatGPT4 enabling some "labs" feature in the Settings. That might get closer to what you want, maybe you can "create a synopsis" of latest docs and preload conversations with it. If you show it enough examples, and you may not need to show very many at all, it can be a great way to go.