Again, the one barrier that I keep bumping up against is that it is almost impossible for me to see how she will miraculously decide to give it a go with me, when she's convinced that she has zero attraction or connection with me... and that it was missing from the start.
Listen, she's in the "fog" of new romance and it totally blocks the feelings that she has for you. You cannot believe anything that they say. Don't let this get to you. My W says the same things. But we both know it's not true. Yes, it's true she has no feelings for you right now and that's because of the OM. When he decides that he is done and wants his family back; she'll be grieving the loss of him. If that happens, you may be right, he might continue just for the no strings attached sex. But if his W finds out; he might end it.
Then the real work will start because she may come back at that point and try to reconcile. she might also go look for another OM. That's not the point however. The point is you've got to look out for you and make yourself better. You will not be able to "work on us" until she decides that she's ready to "work on us."
Just remember all this talk from her about how she never loved you and can't be the real me is justification in her mind to do what she's wanting to do.