The service is primarily aimed at content management or similar applications wanting to support persistent identifiers without running their own Persistent Identifier service.
It is assumed these applications will ensure they keep handle values updated in instances of content relocation or migration. The service while able to support manual management, is not designed around this assumption as the likelihood of individuals maintaining content locations (or other handle metadata) outside a managed environment seems remote.
It is strongly recommended that application developers ensure service outages can be catered for in their applications. While every attempt to ensure the service is running the reality is that unexpected outages will occur.