I've had trouble with KISS backings... because they're not really fully additional voices in the vocal stem.. if that makes sense. The distinction in the sound isn't enough for an AI to easily pull them apart, and I don't have the individual vocal stems, just a main one of them all mixed together. So I've hesitated on doing the other KISS songs for this reason. It's on my mind to try and solve it though. So hopefully some time down the road I will and then I'll make the fix :)