Comment by paperplatter

You still make the same big changes, but the difference is you don't have to do them all at the same time. You also skip the complicated add-ons of ipv6 and don't reassign everything.

Ipv5 as you call it: Phase 1 is getting routers/hosts to understand v5 headers, while users enable v5 and change nothing else. Phase 2 is the transition where people keep using padded addrs while things* are updated in-place to just support longer ones, which doesn't affect users**. Once that's done, we get to use the full space, which some users may ignore and some may use. For better and worse, the existing /32 blocks would still be around initially. Maybe this would appeal to previous ipv4 holders better; they still own the same % of the pie. Maybe 8.8.8.8 would stay forever.

What makes me kinda sure would've worked? Right now, the world has mostly already completed the equivalent of phases 1 and 2 for ipv6. There might even be a way to reuse the ipv6 protocol as-is for ipv5.

* DNS, NAT, DHCP, ARP, routers, VPSes, OSes...

** "User" includes corp network admins, cloud/datacenter operators, ISPs, and simple home customers.