I'm working on an importer for Tiled which imports directly to Unity's built-in Tilemap (and other components). I assign prefabs through script on import to some of the tiles' gameObject property. Because I also create and populate a Tilemap on import, this immediately instantiates the prefab on import, which is fine. However, upon entering Play Mode, the assigned prefabs get instantiated again, while the ones instantiated in Edit Mode also stick around. This effectively means I have two instances of each prefab at each tile. Is there any way to only instantiate the Tile's assigned gameObject in Edit (or Play) Mode, but not both? I'd prefer not to roll my own tile prefab assignment and not having to handle instantiation myself, considering Unity already has the functionality built-in.