Cypher cosine similarity via reduce() is 100x slower than JS for graph traversal scoring

Computing cosine similarity between a query embedding and traversed node embeddings in Cypher using three reduce() calls over 1536-dimensional vectors added 60-90 seconds to burst queries. The Cypher expression was: reduce(dot = 0.0, i IN range(0, size($qEmb)-1) | dot + $qEmb[i] * node.embedding[i]) / (sqrt(reduce(...)) * sqrt(reduce(...))), evaluated per-node in the RETURN clause of an APOC path expansion query.