Log per-request finish breakdown (wait_workers / fallback / wait_rdma) to prove WHY the per-layer transfer stage (~193ms) doesn't shrink vs the monolithic (~172ms) — i.e. whether the workers fall behind the forward (submits land late, no overlap) or the RDMA itself is the cost. INFO-gated. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>