As one who almost walked away myself, I doubt your H is very anxious to go to the C. Hearing positive things about the M doesn't really help a WAS b/c it kind of makes their back bow up and they rebell even more. That's why I don't think C works unless both people are very interested in working in the MR. If he's with OW, I can't see him interested in working on his M. I didn't say that to hurt you, but it is what it is. As you said.....no expectations. However, I think you are finding that to be impossible.
Don't give up hope. I have known cases where the H lived with OW and then go back to his W, so it certainly is not impossible. His feelings for OW will wear off.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!