Using 'sort --unique' I end up with a tiny handful of duplicate lines

I hadn’t figured on adding anything for IPv6 yet, but since it’s made it around the corner, I might as well. Here’s my list of source files minus the ones from Steven Black which you had;

http://hostsfile.mine.nu/Hosts.txt
https://curben.gitlab.io/malware-filter/urlhaus-filter-hosts.txt
https://raw.githubusercontent.com/AdAway/adaway.github.io/master/hosts.txt
https://raw.githubusercontent.com/FadeMind/hosts.extras/master/add.2o7Net/hosts
https://raw.githubusercontent.com/FadeMind/hosts.extras/master/add.Spam/hosts
https://raw.githubusercontent.com/hoshsadiq/adblock-nocoin-list/master/hosts.txt
https://raw.githubusercontent.com/shreyasminocha/shady-hosts/main/hosts
https://raw.githubusercontent.com/Ultimate-Hosts-Blacklist/Ultimate.Hosts.Blacklist/master/hosts/hosts0
https://raw.githubusercontent.com/Ultimate-Hosts-Blacklist/Ultimate.Hosts.Blacklist/master/hosts/hosts1
https://winhelp2002.mvps.org/hosts.txt