I forgot to mention, since you are hardening your system to defend against active attackers, securing your DNS queries is a very important piece of that. Unbound is a very secure resolver so I would recommend taking some time to familiarize yourself with it and optimizing and hardening its settings. By using Unbound, hardening it and only sending queries out through a VPN you are probably effectively impervious to DNS attacks from the massive majority of hacking. Check out this article and here are some suggestions for settings. https://calomel.org/unbound_dns.html
Enable DNSSEC Support (this is authentication for your DNS queries to avoid spoofing attacks, kind of like SHA)
NO Forwarding Mode
NO DHCP Registration
NO Static DHCP
Hide Identity
Hide Version
Prefetch Support
Prefetch DNS Key Support
Harden DNSSEC Data
You might be interested in the Unwanted Reply Threshold, but I've never used it and know nothing about it
Experimental Bit 0x20 Support