In addition to the choices for how to chunk (i.e. defining chunk size, chunk boundaries, chunk overlap, etc.), there's also the question of what actually gets returned once finding the chunks that match. For example, perhaps I have a document with 100 1-page sections where each section is broken into roughly 5 chunks. I may get optimal performance in my RAG application not by retrieving the top K chunks from the index, but rather by returning the top K sections fom the document, where sections might be scored based on the number and scores of child chunks. It also might be useful to incorporate section summaries, etc., in the retrieval process.