tracking multiple identical images with ARImageTrackingConfiguration

Hey there,

I'm working on a demo using the new `ARImageTrackingConfiguration`, where some of the `ARReferenceImage` might occur multiple times in the scene.

I've set

let configuration = ARImageTrackingConfiguration()
configuration.maximumNumberOfTrackedImages = 4
configuration.trackingImages = [warrior, rogue, mage, barbarian, skeleton]

But, if I put two identical skeleton-images on my table, only one of them will be detected!
Is this an implementation constraint of ARImageTrackingConfiguration , or is there a trick to track mulitple instances of the same image in my scene (i.e. playing cards?)
Thanks for your help!