Currently, the variable user_unnamed_ip is always null for the actions createaccount and autocreateaccount. However, I believe that for the creation of temporary accounts (which are autocreateaccount actions), this variable should be accessible.

Use case:

1. Ban temporary account creation via a specific VPN recently used for abuse, using variables from the IPReputation extension.
2. Exclude certain IP ranges from this ban.

Currently, this kind of exclusion is impossible and the only way is to nullify the first condition altogether. In addition, temp accounts' IPs can be revealed on Special:Log/newusers, so I don't really see a strong reason to keep user_unnamed_ip inaccessible for temp account creation.