This describes the state of mind that a lot of the WAS are in it seems, so many stories of returning spouses wanting to work it out but giving way less than 100%. It's like they come back to prove to themselves that it won't work, but get frustrated when things go so well, because it goes against their original plan. It can be so hard to reconcile what they say with how they act.
I think that she is and will continue to act out. I view it much like a teenager rebelling and bouncing off the walls. She really does sound like she has a MLC to some extent.
Your insight into WAS and feels so wrong to feel so right is very good! That explains a lot. Ultimately if you keep up the unconditional love, she may decide that the "feels so good" is too important to loose. I am sure that many WAS ultimately realize that if they truly leave, they may never again find that "it feels so good" in their life and they decide they need to change to capture and cement that part of their life.
Good luck.
>43 years of marriage--My wife and I are now closer than we have been in decades. I believe that my SSM is over.