If you want to do this, I recommend instantiating a prefab that isn't in the scene. That way it won't already have a render data reference in there.
In any case, it really isn't recommended to instantiate tile maps like this especially not for a runner game - instantiating a tile map section will take a fair bit of time and your game will likely stutter. You're probably not seeing that now as it isn't actually generating the data as it thinks it already has render data - the render data which of course belongs to the thing you're instantiating from.