The server doesn't boot natively.
It can boot in Linux rescue mode. So:
qemu-system-x86_64 -enable-kvm -m 65536 -smp 16 \
-bios /usr/share/ovmf/OVMF.fd \
-drive file=/dev/nvme0n1,format=raw,if=virtio \
-drive file=/dev/nvme1n1,format=raw,if=virtio \
-netdev user,id=net0,hostfwd=tcp::80-:80,hostfwd=tcp::443-:443 \
-device virtio-net-pci,netdev=net0 \
-vnc 127.0.0.1:0

A couple of lines modified in /etc/rc.conf and /etc/pf.conf

And the server is responding, while waiting for the KVM console.

A VNC view of the top on the server - now running inside a VM
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