Failover for PI Connector Relay
Although, the PI Connector Relay going down / not being available does not cause data loss since the connector data is buffered, if the source connector supports Failover, the relay becomes the only single point of failure in the data flow.
Having an HA option for the PI Relay would allow for a more robust architecture.
This functionality is not currently planned.
After having interfaces with failover functionality I find it hard to believe anyone would switch over to these technologies (PI System Connector and the PI Connector Relay) and accept host maintenance downtime on the dataflow from the PCN to a BLAN.