ML-DSA-65 certs are 10x bigger than ECDSA but add no latency on real WAN networks

The pqc-bench experiment found ML-DSA-65 certificate chains (7.68 KB) are 10.4x larger than ECDSA P-256 (741 B), yet handshake time at 70 ms and 148 ms RTT is statistically identical. The reason: the chain fits inside TCP's initial congestion window of ~14.6 KB and ships in a single round-trip.

• ML-DSA-65 cert is 7.68 KB vs 741 B for ECDSA P-256 — a 10.4x increase
• At 70 ms RTT the delta is just 0.7%; at 148 ms it is statistically zero
• At same-AZ latency ML-DSA-65 adds ~1.5 ms per handshake (+89%)
• Breakage expected only above ~15 KB certs, e.g. SLH-DSA at ~17 KB