I use Unbound locally as a DoH server. The Alpine Linux Unbound package is compiled with libnghttp2, required for the built in DoH listener. That's more than enough to enable ECH [1].
I pre-cache all the domains I use hourly via cron. My ISP is not going to dork with my DNS requests and their employees are bigger deviants than I. If I ever started browsing the web from a phone I would just set up my own public DoH server. It only takes a few minutes and gives me my own query logs for debugging weird issues.
[1] - https://tls-ech.dev/
Unbound has "prefetch" which will refresh near-expired cached records, and various other cache/ttl knobs. "serve-expired" seemed to work well too
> I pre-cache all the domains I use hourly via cron.
How does this look? Shell script querying a list of hostnames? What qualifies as a domain you use?
Why pre-cache? For speed... what is it, 30-50ms at most? If the authoritative server's TTL is <60minutes, do you force it to 3600? Do you audit all the connections that occur for every website you visit, collect all the domains hosting assets, and pre-cache those as well, or is the main site's domain the only critical one because that affects perceived latency the most?