Man, I love Kagi. Two years ago I would never have thought I'd ever pay for a search engine, but the option to block garbage domains like userbenchmark or sites with purely AI generated content is just too good.
If you go to duckduckgo.com/settings you can generate a URL with all of your saved settings. Loading it will configure all the settings it includes in your browser's local data. Blocked sites are included, I just checked.
It always takes me awhile to remember where this setting is buried in their menu. In case it helps someone else: https://kagi.com/settings/user_ranked . Besides blocking, they have ranking adjustment options on this page as well.
https://ublacklist.github.io/docs/getting-started