How to manage duplicated Stages?

I want to spawn 8 mole instances randomly at OnAutomaticHitTest callback. Core sample project is seems to be made for only one product placement, so plz give me some hint. I copied HandleInteractiveHitTest into AutomaticHitTest. With contentPositioningBehavior.DuplicateStage = false(sample's default), only one mole spawns automatic and moves wi camera. With contentPositioningBehavior.DuplicateStage = true (with frequency suppression), successfully moles spawn randomly but I can't delete old mole. Can I hold old duplicated content (and planeAnchor)'s references and manage them individually?