LocalSignalSender

The in-process SignalSender: a signal whose origin is this node of this service goes straight to its registry; any other goes to remote, the sender to other nodes' internal signal entries (and 6.6), which drops it by default.

A node id is unique within its service only (its lease groups are the service's), so two services may both have a node-1 when their ids are configured: the origin's service must match too, or a signal for another service's wait would be dropped here. Without a service, the node id alone decides, for a node that serves no other service's waits.