Unity Sync Replication on SANCopy target

Hi, I'll be migrating VNX5700 to Unity 300F. The current VNX5700 has MV Sync replication to a DR site VNX5700. Unity 300F will be replacing both the VNX5700 and MV will be replaced with Unity Sync Replication.  I intend to use the new SANCopy Import feature of Unity at Prod site. As part of the migration, I need to test the DR host on the same day when the Prod host is migrated to Unity. Will I be able to setup Unity Sync Replication on the Unity LUN (SANCopy Target) while the SANCopy is Pushing data from VNX to Unity. To save the downtime window I'll need to start the SANCopy session and the Unity Replication atleast few days before the cutover day.