I'm no expert, so I'm not sure if I'll explain it correctly. But I've been using docker swarm in a server, I use traefik as reverse proxy, and it just doesn't seem to work (I've tried a lot) with ipv6 (issue that might be related https://github.com/moby/moby/issues/24379)
A really cool way to do it is how Yggdrasil project does it (https://yggdrasil-network.github.io/implementation.html#how-...). They basically use public keys as identities and they deterministically create an IPv6 address from the public key. This is beautiful and works for private networks, as well as for their global overlay IPv6 network.
What do you think about the general approach in Uncloud? It almost feels like a cousin of Swarm. Would love to get your take on it.