Comment by toast0

Otoh, ipv6 address assignment tends to be much more contiguous. My (small) residential ISP has one v6 prefix but several v4 prefixes. If you block the whole prefix for services you don't like, it's far less prefixes for v6.

But, it is a new skill, and you can turn off v6 at small cost if you're already ok with heavily restricting v4.