I don't see how the loading works for the end user's custom dataset. In fact, I find the layers of abstraction you have between getting the finetuning dataset and the actual training very opaque. I can't even tell where the dataset is coming from, it doesn't appear to be an example local to this repository.
I think a lot of people what something like... "drop .txt files of example data to train on in this /folder/ and run python finetune.py /folder/