Exploration mode uses entropy search to explore the latent space (used for evaluating the LLM on the selected corpus to evaluate), and eploitation mode is used to figure out how well / bad the model is performing on what regions of the selected corpus.
For accurate evaluations, exploration is used. However, I'm also working on a visualization too s.t. users can see how well the model is performing at what region (courtesy of gaussian process models built in by bayesian optimization) and that is where exploitation mode can come in handy.
Sorry for the slightly messy explanation. Hope it clarifies things!