Thank you for the kind words. I plan to update that post at some point, haven’t looked at it in a while.
I did take a look at your request to use IPv6, and there doesn’t seem to be an equivalent to FIPv4Endpoint for IPv6. There are ways to convert IPv6 addresses to their IPv4 equivalent but that is only if the IPv6 address has an equivalent in the IPv4 range.
Those methods aren’t necessarily supported by UE, but you can use outside libraries and custom code, so if you can get it to work there are options. You can find some just by searching converting IPv6 address to IPv4. I’d make suggestions but I’m not sure what your use case is exactly, but a quick search gave plenty of examples to look through.
Hope this helps. Good luck.