The only problem with that is that it does not appear that there is enough equity in the house, at this time, to make any kind of refinance possible, unless his ex has cash to add at the closing table. Therefore its almost a no win situation. He can force a sale, but he would probably have to take cash to closing, or risk a short sale which would effect his credit.
OP, can your wife realistically afford to pay for the mortgage by herself? Is she responsible with money? If the answer to both of those questions is yes, you might want to agree to allow a few years to pass until she refinances, so that she will actually be able to do so. That would give some time for a little bit of equity to build, even if housing values don't increase.
She was advised by the mediator to try for a "rewrite", which is supposedly different than a refi somehow. I think she can do it, capability-wise. As for being responsible, that's something yet to be determined. I'm former Navy, and she would handle the money while I was out to sea. Well, I had to take it back over after we bounced several checks due to her inattention to matters. I've been the only one handling the finances for over a decade. She's been back in it for maybe three months.
While I'm in here, does anybody have any notions about my other questions?