If you have multiple machines with their own IPs, v4 or v6 makes no difference. If you have a single machine (vhosting), the number of IPs and their type makes no difference.
I will quote the comment you are trying to justify:
> With ipv6 they can now be fully scaled easily but they are absolutely awesome, much easier to scale because you can give your client a simple list of sse services and its essentially stateless if done right.
If you don't understand it either please stop saying random stuff about IPv6 that we already know and has nothing to do with this thread.
How is it limited? How is it less limited with IPv6?
A client gets an SSE endpoint (hostname). That endpoint maps to an IP. A server at that IP receives the connection. Which part is better with v6?
Are we talking about the few cents it would cost you to give each server an IPv4? Are we thinking about a distant future where that cost is not negligible compared to the cost of compute? Something else?
So that was the only argument. Wow, I'm glad I finally got to it, but I'm not amazed. All it took is making it up myself.
I don't use AWS so ok thanks. And if I did, I would use their ingress/gateway solutions, which totally circumvent this problem (while being quite expensive anyway).