Re: Workstation, Server, and Router Options
You probably want to look at dnsdist for DNS load balancing. It's a great solution. I use it in a few different application environments, in front of small cluster of active-passive Stubby instances which provide DNS-over-HTTPS (multiplexed HTTP/2 connections if your upstream DoH resolver supports it).
DNSdist - https://dnsdist.org
Stubby - https://getdnsapi.net/blog/dns-privacy-daemon-stubby