I don't think you are refuting my claims. If you put the extra 4 bytes of address at the end of the header, telling the legacy software that the header is now bigger doesn't mean that it will use those bytes for routing. Hence it will route to the IPv4 address. Hence if we send to a.b.c.d.8.8.8.8, it will actually get sent to 8.8.8.8.
IPv4+ packets wrapped in IPv4 is just 6in4.
And all the handwaving is exactly that. It doesn't solve the actual problems that OP claims, e.g. being able to keep existing scripts and everything just works. If anything it makes those systems far more fraught. IPv6 does allow an admin to keep all those scripts for IPv4 and have them still just work.
If anything, what this whole thing shows is that many network admins don't know what the fuck they are doing and are relying on existing scripts and cargo culting.
IPv4+ packets wrapped in IPv4 is just 6in4.
And all the handwaving is exactly that. It doesn't solve the actual problems that OP claims, e.g. being able to keep existing scripts and everything just works. If anything it makes those systems far more fraught. IPv6 does allow an admin to keep all those scripts for IPv4 and have them still just work.
If anything, what this whole thing shows is that many network admins don't know what the fuck they are doing and are relying on existing scripts and cargo culting.