Geez, color me double-wrong. Yes, that should be plenty. I thought was a VPN-esque solution that required shuffling all traffic through the VPS instance, but yes you're right, it's basically just a custom DNS server. In which case this would be totally fine. I might even try it myself if I ever decide to unroot my phone.
DNS66 (https://github.com/julian-klode/dns66) doesn't require root. It uses the Android VPN system to capture DNS requests and forwards everything else.
