https://github.com/AGWA/snid

So you basically have a cloud server and a domain with a wildcard record, and you then forward IPv4 through IPv6?

I think this somewhat proves my point that IPv6 doesn't solve much for self-hosting. You still need some kind of working IPv4 setup. You are using IPv6 in place of either a reverse proxy or something like tailscale, which I suppose is more convenient.