Why Encryption is important? Read https://spreadprivacy.com/what-does-https-do. It explains why sniffing on the line can only be mitigated by using encryption wherever possible.
As of the IPv6 bug, I can currently not use Let’s Encrypt to automatically refresh my certificates on my servers. My network is behind a IPv6 only stack, IPv4 cannot be connected/routed from the outside without a tunnel provider.
My actual workaround is to use the AAA records of my domain to store a key value generated by Let’s Encrypt to verify my domains. With this manual workaround I can at least generate a new and/or update a certificate. This workaround should not be required anymore since certbot 0.15.
sudo pacman -Sy certbot