Yes, good providers give you a real /48, routed to a link-local address, so it's all under your very own control, trivial to create subnets, tunnels, whatever,

Yes, good providers give you a real /48, routed to a link-local address, so it's all under your very own control, trivial to create subnets, tunnels, whatever, without any need for any hacks whatsoever. As for the NDP proxy hack being easy: Well, sure, there are more difficult things (and yes, I once wrote an NDP proxy deamon myself, which wasn't particularly difficult either). But it still adds complexity, for no real reason. The question isn't whether you can work around this deficiency. The question is: What is the point of this deficiency in the first place? Plus, you still only have one /64, which is just braindead. And, with a proxy NDP setup, you are vulnerable to NDP cache DoS: Your upstream router needs to do NDP resolution for each individual address (instead of just the one router address that your prefix is routed to), which enterprising attackers can DoS by simply sending packets to a few thousand to million of your addresses which then will overload the NDP cache of that router, leading to your machine(s) potentially being unreachable.