I see where you're going, but I think you have equally a concern for all containers being returned; there are just fewer of the own use ones. That may indicate there's more product left in those containers, and we're not able to return them because there's still product there. Is that the case?
What are the penalties if someone is actually found to be in violation of bringing in more product? There could be situations where, if frost had occurred earlier than was anticipated and someone were caught with product in their storage, there would be a reasonable explanation. Is there a penalty section here that would apply? How would you deal with someone who's in violation of the general principles?