If you haven't run into this yet, be aware that Select Portfolio Servicing (SPS) with Chase backed assets have a new guideline that can throw a wrench in the transaction. They are only allowing one short sale review! Meaning that if the buyer walks or if the deal is denied for a low offer, you won't be able to try again.
I had an approval and the buyer walked then they would not allow us to submit at the same terms due to this guideline. We also had a buyer get countered, the buyer only raised their offer slightly, they would not counter gain, and they closed the file out.
Be cautious as they won't tell you these guidelines ahead of time or about the only one counter rule!