Ah. So, you're saying that what you describe doesn't actually exist. That the best you can currently do is stuff like [0] and [1] where the IPv4 or IPv6 client use v4 or v6 addresses (respectively) and an intermediary sets up a fake destination IP on both ingress and egress and does the v4 <-> v6 address translation.

If so, that was not at all clear from your original comment.

[0] <https://docs.fortinet.com/document/fortigate/7.6.1/administr...>

[1] <https://docs.fortinet.com/document/fortigate/7.6.1/administr...>