Thanks for the thoughtful read — and yes, the tool is focused on caching / recursing resolver performance, not authoritative. The asyncio + dnspython stack makes it easy to script and monitor those behaviors over time. Running your own resolver is definitely the gold standard if performance and control really matter, but benchmarking public ones helps surface the trade‑offs users face in practice. The 300ms example was more about illustrating how ads and systemic factors can dwarf raw resolver speed, not a claim about per‑request DNS overhead. Appreciate the detailed perspective and glad the doc came across clearly.