Anything smaller than a IPv6 /48 is effectively unroutable. Your ISP has to route smaller blocks, like /64s, privately (because only /48s hit public bgp). And t

Anything smaller than a IPv6 /48 is effectively unroutable. Your ISP has to route smaller blocks, like /64s, privately (because only /48s hit public bgp). And then you have to route the /64 they assign you privately once again.