Cool. Do you do any of the relevance calculations directly, or is that all handled by Weaviate? If so, is there any way to influence that part of it, or is it something of a black box?
https://github.com/Dicklesworthstone/fast_vector_similarity
I've had good results from starting with cosine similarity (using FAISS) and then "enriching" the top results from that with more sophisticated measures of similarity from my library to get the final ranking.