Interesting. I did finally find a use for IPv6 which I wrote up here: https://martinalderson.com/posts/i-finally-found-a-use-for-i...

Tbh though the docker problems are very serious and extremely painful to work around. Everything works great apart from Docker which has so many issues - it does not handle IPv6 inbound but IPv4 out well at all (at least as far as I can tell!).