You can set a custom URL to use Ollama which is OpenAI API compatible. Llama3 8b runs quite fast for me on a M1 Max. I'll be making use of this feature I think (haven't tried it yet).
Note that to make use of ollama, you'll have to wait for the next release or upgrade to a beta release --- while you can change the API right now it's using a newer format for the payload, that's fixed in the beta/next release.