So yeah, this troubleshooting guide absolutely slaps - DNS is basically where all your silent failures go to hide, and the author nailed it by splitting out proxy testing from client-side testing. That APNIC stat about AAAA failures hitting 64.2%, that's the kind of we need to change how we do this data point that actually moves the needle operationally. To really level this up tho, you'd want some solid workarounds for IPv6 headaches like just yeet-ing those AAAA queries and going A-only, a breakdown of how EDNS Client Subnet messes with geo-targeting, and a heads-up that DoH straight-up bypasses proxy DNS in antidetect profiles. One more thing, google's sitting on like 68-70% of the open resolver game, so saying nearly 50% is kinda lowballing it