Or you set up DNS64/NAT64/464XLAT on your IPv6 end of things, and those on IPv4 side don't have to do anything.
Or you set up DNS64/NAT64/464XLAT on your IPv6 end of things, and those on IPv4 side don't have to do anything.
You can have a front-end with IPv4 and have a box send the request to the back-end which is IPv6.
This is how FaceMeta works for the last few years: they are completely IPv6 internally in their DC and only have IPv4 at the edges to service 'legacy' connections.
* https://www.youtube.com/watch?v=IKYw7JlyAQQ
* https://engineering.fb.com/2017/01/17/production-engineering...
And I still don't get any-to-any connectivity with the IPv4 people, which is what you need if P2P is going to be seamless.
You don't have to install NAT64 to connect to v4-only hosts -- you can run dual-stack, and use your existing v4 setup to reach them. NAT64 is just what you do when you want to turn off v4. You said in the post above that people running networks should have been told they had to change things, so you don't get to whinge about needing to do it yourself.
Also, you don't need to have a public v4 address for v4-only people to connect to you. Reverse proxying is a service you can pay for, and only the people running the proxy need v4. CloudFlare do this (for free, even, depending on what you're doing).
In fact the same is true of NAT64; set your DNS server to e.g. 2a01:4f8:c2c:123f::1 and away you go.