It seems X-Forwarded-For and X-Real-Ip shows the IP of badger when resources are accessed by IPv6.
Beta8

wget -4 whoami.mydomain.com
...
...
X-Forwarded-For: 193.193.221.3
X-Real-Ip: 193.193.221.3
...
...

wget -6 whoami.mydomain.com
...
...
X-Forwarded-For: 172.18.0.1
X-Real-Ip: 172.18.0.1
...
...