Hey Harrison,
I’m working on something similar! As of this post you can now continuously fine-tune the same model. Just specify it again when you issue the tuning job object.
While the results I’m seeing are mixed, I suspect strongly that lots of data will make GPT-3.5-turbo a fine-tuning beast. Good luck!
I’d also suggest prompting GPT-4 with in-context examples of what you want. In this way, you can kinda build a tabula rasa classifier.