When trying to decide whether a range of IPs should be blocked, it would be useful to be able to see all (recent) contributions from that range. With a single person often having an entire IPv6 /64 block, this becomes even more important.

The UI for this would probably be a dedicated special page that works very similarly to Special:RecentChanges, except that it's for anonymous edits only, and has an IP filter. Adding these options to the existing RecentChanges page would probably make an already complex interface even more complicated.

This is different from T171382 which proposes consolidated user contributions per /64 range. The rationale is that

1. we should avoid a fixed range size, since we may want to assess a bigger range, or focus on a more narrow range
2. permanent records of user contributions bound to an IP are only useful for static IPs. For the vast majority of IP addresses, 30 days of recent changes should be sufficient.

See also T112325: Have one aggregated talk page for ipv6 /64 and T171382: RFC: IPv6 contributions and talk pages