A DNS service could round out the Kagi product portfolio nicely. Kagi search already has great personalization, this approach could be applied to DNS filtering/whitelisting/blocklists etc.
My personal experience with AdGuard DNS and NextDNS range from manually setting DNS with IP address, and installing user profiles (macOS and iOS) which has done well to circumvent sticky ISP DNS enforcement. These are great products but clearly compete for users, and I think incorporating into the Kagi family might taste better (like Kagi Pass in search).
Allow users to manually set their DNS addresses to point to a Kagi destination, either through direct configuration or device profile. AdGuard DNS and NextDNS are very good comparators, so good that one might wonder if having a Kagi-ized DNS option is needed - but I think tying it into search functionality might be a clever enhancement.