I appreciate the replies, I really do. I'm trying to avoid a lawyer with this obviously but, it seems it is a situation that only a lawyer would know. I'm hoping someone comes through.
Let's say the ex-petitioner does not cancel the request, then how long does it stay in limbo? I don't want to burn 530 to be told "sorry, there is someone who has applied already."
The sad part is that only the petitioner can cancel a visa application. She can't. So, what happens if he just let's it die? How long before it is safe to apply? I honestly only think someone who works at immigration or a well seasoned lawyer will know. At the cost of a lawyer, it would be cheaper to apply 2x. Then, I can share here and let everyone know.