[Dagger2]

  ::203.0.113.42 (tunnels to 203.0.113.42 over v4)
  ::ffff:203.0.113.42 (opens a v4 connection via an AF_INET6 socket)
  64:ff9b::203.0.113.42 (translates to v4 at nearest NAT64 point)

What are these then? Also, it's not like they had a choice here. v4 is hardcoded to 32 bits, so the option of making a single network with a bigger address size wasn't available.

I think I can count that as falling under both "something it already does" and "something that's impossible".

Your laptop will just get some IPs as appropriate for the network it's on, and then it'll use them. You don't need to think hard about it.