The confidence interval on the reranker effect, -0.079 to +0.073 over 16 queries, is the part worth flagging loudest, because plenty of RAG writeups report a directional win or loss off a sample that size without ever checking how wide that interval actually is. On the changed-your-mind case you opened with, a newer post superseding an older one you haven't retracted, the EXPIRES_AT filter only catches explicit expiration. Does the fused ranking end up handling that case on its own, with the newer post simply winning on relevance and recency signals, or did you still need something like an explicit supersedes pointer between the two memories so the older one gets excluded rather than merely outranked?