I gave her numerous opportunities, kept moving the poles but every rope comes to a point when it just snaps. And I think I already came to mine. She keeps asking me what she can do to make this right and I have no idea.
She knew what to do but didn't do it. This is her words from your first post : "Told me she now realises this whole mess could have been avoided if she were honest." Since the same thing has happened several times, it seems that she didn't really realize it. Moreover, this is the best of the possibilities. If she had realised this but continued to lie, she knew that honesty will not save the situation and the truth will make things much worse.
What I can't understand is why she nuked our R on her own. I would never know about most of what she told me, she covered her tracks pretty well. I would say either the threat of poly or her guilt pushed her to come clean.
The threat of poly of course. Think about the previous TT's. Were they also said out of guilt? There is an unnoticed point here; when a piece of truth is told, untold pieces are still hidden. Of course, she is well aware of this. Revealing a little truth in the name of being honest in order to hide a more important truth cannot be done with a feeling of guilt.
Each time, looking into your eyes, knowing she was lying, she said that she had decided to be honest and had nothing else to hide. She always gave the truth bit by bit to see how much would be enough for you. Sorry, but that's not a good sign of personality.
The only downfall I find worth mentioning (never noticed before) is that my new attitude makes her VERY bothered, in the good sense. I have never subscribed to that alpha/beta paradigm, but maybe there is some truth in it. At least when it comes to my wife.
I also don't like this type of naming. But these facts were known long before they were called that way.
Now your WW sees you are done with TT and you don't care about the rest. That's why she is bothered. She was probably planning to give you enough truth to keep you in marriage. She can no longer continue to TT unless you allow her. Therefore, I wouldn't recommend asking questions about the A. Just accept it as if the worst happened and continue the D steps. Let her find for what needs to be done, until you are satisfied. If she can't or doesn't want, D is already in process.
If the truth is horrible for you and D is inevitable when told, she has two options; she tells it and takes her chances for the hope of R or she agrees to D sticking to her story and hopes for being friends in the future.
Couldn't the whole truth really be only that much? Even so, she caused it by bringing it this far, this way. She has no right to complain.
I pretty much know her motives for lying - fear and self-preservance.
This fear and self-preservation motives didn't come into play at first, though. She didn't end the relationship when you had doubts and fights with her about it, but she did only when she was caught.
She kept it in her desk at work. Charged it there, too. But she WAS using it at home, quite often actually. I can't believe I didn't notice. She kept it in her walk-in closet, hidden in one of her shoes.
The questions that struck me here is why didn't the messages sent by SH's X-GF show the next stages of the A? Where were the pictures? Was SH also using burner phone?
Did they study not only not to get caught, but also what to do in case of being caught? Could that "we went too far" messages have been specifically left on the phone to give the impression that they are not going any further? But if it were, SH would delete the ILY messages so that his X-GF wouldn't see it. A bit complicated...
I have said several times that you coped well with this situation from the very beginning. You say it like you're just getting started, but you're actually acting like an alpha male from the very beginning. That's why my view about your future is always positive. I know that no matter what decision you take, you will come out of this situation as strong as possible.