If your firewall can do NAT (and spoiler alert: it can) then it has stateful logic built in. Maybe some of the really early home stuff didn't support it on IPv

If your firewall can do NAT (and spoiler alert: it can) then it has stateful logic built in. Maybe some of the really early home stuff didn't support it on IPv6, but that's long in the past. If you're worried about IPv6 using to exfil data then you're well beyond a great many administrators in locking down the network. Usually malware just exfils on IPv4 HTTPS because that's already allowed, and it's only avoided in places where the deep packet inspection services only run on IPv4. This is where you see a lot of corporate pushback on IPv6. The Deep Packet Inspection vendors have been very slow to adopt so corporate policy is often just to block all IPv6 period. I won't argue against a lot of home routers having egregiously bad firewall configuration UIs though. In IPv6 a /64 is special. It's the smallest network you are supposed to allocate. Some people think it is the equivalent of an IPv4 single address, but this isn't quite right. It is still a full subnet. It is better thought of as the IPv4 /24 behind a single NAT address. Home administrators are expected to put all of their hosts on it. Assigning a /64 to each client is not supposed to be a typical use case, and would be mostly to avoid having the clients inter-communicate. The problem however isn't wasted space, it's just that you'll exhaust your typical home /56 too quickly. I can see you're concerned about running out of IPv6 addresses due to excessive waste, but we've not even scratched the surface on them. The address space is mindbogglingly huge. A lot of the optimizations we have to do to save space with IPv4 are simply not relevant in IPv6.