Syncing external instruments via MainStage 3 with clock from external source

Mainstage 3 and 2 can be synced form external source (ex. drum machine). You can connect to Mainstage both version also external midi instruments using dedicated stripes. They should be synced also with mentioned clock. But you can do it only in Mainstage 2. In new version 3 it does not work. Has somebody any idea how to do it now?