If there has to be a separate route for each one anyway, why not just
blow 253*10 addresses and announce a /24 for each root name server, even
if only one IP out of each /24 is used?
Less CPU to blow holes in filters that normally deny > /24.
How far does this get extended, then? What if, to encourage aggregation,
/24s start to be filtered? Do you then blow a /23? A /22? I guess the real
question is how do you balance between two scarce resources, router CPU and
IPv4 address space.