I agree that tackling just one book is not a solution to this problem.
The problem is that people are able to stack any book with the same name.
At first I thought that trained books were the only books that could be stacked together, but ofcourse Trained books itself were never the issue, but that's why this topic was created as it was the first case that we recognized and support didn't answer any mails about it for a long period of time.
Over the past few weeks it has become clear that the problem is much bigger and that a bugfix that affects all books is the only solution, Trained books can and should remain usable afterwards.
So again I urge Con to come up with a solution to this exploit quickly, cause who knows how many people are using it right now.