Using an SVC split cluster connected to one IBM i instance is supported. Using an SVC split cluster and managing the connection between multiple IBM i instances manually is not supported, and we have no plans to support.
We have announced support for SVC LUN switching in PowerHA as a 7.1 PTF built on top of IBM i 7.1 TR6, which was made available mid-year 2013. This support allows for management of the LUN switch through PowerHA and manual management of a switch between SVC nodes. We are considering a solution entirely managed by PowerHA in a future release.