Appreciated the honest framing in section 3 — the realistic-expectation note that most of the win for small webhook payloads comes from fewer syscalls, batching and multishot receive, not from zero-copy itself, is exactly the kind of caveat that saves teams a painful port. The checklist for zero-copy receive is also genuinely useful: Linux 6.15, NIC header/data split, and the SINGLE_ISSUER, DEFER_TASKRUN and CQE32 flags together mean it is not a drop-in switch. One thing I would add from operating ingress in practice: the backpressure table's fast-fail with 503 and Retry-After is the right call, since sensible senders retry on 5xx — accepting work you cannot drain just moves the queue into your own process. Good piece.