EAPTSD, there are a few people who can't or won't D in a similar situation as you. DrgnHeart is one of them and her thread in General titled "Childish but felt good!" has a long discussion on it right now about doing exactly what you want to do so I'm going to give you similar advice.
First, you have to be BRUTALLY honest with yourself about the situation. I can see that you're not there yet because:
Another A wouldn’t be a dealbreaker
When it does I am prepared to set and enforce hard boundaries including D
This completely contradicts itself. Either you WILL or you WON'T file for D in the event of another A. Don't threaten in order to get R. Don't bluff. Decide sooner rather than later that an A either WILL or WON'T result in papers being filed and be prepared to stand by it. If it's not a deal breaker, it's not so that means you no longer have any leverage to use when bargaining with your WW for R. If she doesn't know this, she will very quickly find it out when you threaten, she has the A anyways, and you don't file. So don't even pretend like this is a potential consequence for her unless you are dead set on making it one.
What I value in having my WW under the same roof wouldn’t disappear if found out she was chatting with some guy for a couple hours a night after the kids go to bed, that is who I understand my WW to be even if she isn’t actively doing it right now.
I want you to notice something - what you described is the ABSOLUTE BEST case scenario if your WW was to cheat again and it doesn't matter at all that this was what her first EA was like. Escalation is the norm. Have you even thought about what you would do if the guy was local and she was sneaking off to rendezvous with him? Has it occurred to you that there is a very good chance that any EA she has could culminate in her separating, moving in with OM, and sending you D papers? This idea that you have in your head about what it might be like if she cheated again needs to be yanked back down to reality and examined. Would you still feel nothing if she was going on dates, giving OM #2 compliments, gifts, and avoiding any physical intimacy with you in order to stay faithful to him? How about if she makes plans to run off and leave you holding the bag? What if she intends to leave the kids with you or worse, take them with her to a far away place that would make co-parenting extremely difficult for you?
You need to LOOK at all of the possibilities and risks you will face if you allow things to slide into a new DDay otherwise you will leave you and your children vulnerable to her selfish whims when the time comes. I don't know how much you read here but there are tons of examples of WSes who played the long game, hid assets, spun lies to friends and family, filed false DV charges, and absolutely wrecked their BS's life in a D or attempted to like Vonbock's STBX who tried to get him to help her buy a new house for her and OM by saying it was a business opportunity. Yes, they are not the majority but they are common enough that sometimes you really can't predict what your WW will be capable of with a savvy and scheming OM in her ear encouraging her to set them up with the best life possible regardless of what it does to you. We get a new BS with a WS who at least attempts to blindside them in order to get a better D outcome once every couple of months. They are not rare enough to be ruled out just because your WW didn't stoop that far low yet with her EA.
Which brings me to my next point: See a lawyer for a consult. Be honest that you don't want to D but a D might still happen and be initiated by your WW in the future regardless of what you want. Know what you would be entitled to. Know what to do if you come home to an empty house, all of your furniture gone, and a note from her saying she's left you for Joe Schmoe. Create a new bank account that she doesn't have access to and put a few grands of "Oh Shit" money in case you need a lawyer on retainer ASAP. Because if you really do wind up with an ABSOLUTE WORST case scenario and one of the many things explored above does happen, it is MUCH more difficult for you to track down the time, resources, and energy to get this going while the clock is already ticking. Time will make the difference when it comes to safely avoiding having your kids taken away and not seeing them for 6 months due to an apathetic police force and slow courtrooms.
For your own sanity:
Get an IC. Nail down your deal breakers. Make your escape plan. And also importantly - start treating your WW FULLY like a roommate. No more hugs, kisses, cuddles, or holding hands. If it would be weird to do with someone you live with and don't even like that much, you don't do it with her. No more spending time together unless it is STRICTLY for the kids. Send a CLEAR and STRONG message to her that her refusal to follow through on what was promised means that she is no longer entitled to your love and affection as a spouse. Read up on the 180 and follow it.
When she tried to hug you, say no and move away from her. When she tries to kiss you, say no and turn your cheek. If she goes to hold your hand, you move your hand away. And when she asks why, choose something like this to say: "I'm not interested in being anything more than a roommate to you. If you book and attend 3 IC sessions, I might be more interested in discussing it." "I'm not feeling it right now. If you read "How to Help Your Spouse Heal from Your Affair", I might be more open to hugs and kisses." Choose anything she's promised you and repeat it any and every time she asks. She will either do the thing you want her to or give up entirely and stop bothering you for husbandly affection she has not earned. NEVER promise anything. Always keep it vague. If she reads a book and you still don't feel like changing your relationship past that of a roommate, pick a new promise she hasn't fulfilled and use that instead.
If you DO NOT do this, a couple of things happen. The first is that your WW has zero motivation to do anything differently. She has her EA, gets to make all the false promises she wants, and you still toss her love and affection from time to time. She doesn't HAVE to do anything because you're still here, being her husband. So what if you don't sleep with her anymore? She clearly could care less maybe because she's getting her needs met in other ways. Maybe that's porn, erotic novels, a toy, and/or a new OM. Point being - a year is long enough to know that she isn't really missing the sex so you need to start cutting out whatever else is enough for her to think it's okay to keep sitting back and allowing limbo to progress. Make being married while refusing to R less comfortable for her.
For you - it stops the cycle you have found yourself in which is: things improve a little, you get a hit of hopium for R, nothing changes, you get a disappointment crash. If you stop allowing for anything in the marriage to go back to normal, if you cut out everything that makes a marriage a marriage aside from a piece of paper, you will stop the hopium-disapointment cycle AND you will care less and less about what she is doing and how she feels about it. Then if and when a new DDay comes, you will be able to safely enact a consequence/get out of infidelity/not care because it's not really a deal breaker. You will also be able to stand strong if she does break of your non-negotiable lines in the sand because again, you will not care if she gets upset or sad or begs for you to reconsider in part because you gave her a clear road map to R, you showed her what she was missing out on, you warned her of what would happen if she did not comply, and she still did it to herself. You will no longer be responsible in any way for the consequence of the marriage ending and she will have no one else to blame but herself.
I'm going to be honest with you - I don't think choosing to do this is healthy or should be recommended. It's going to be extremely difficult and I can tell that you're not quite where you want to be yet. You're not as detached as you seem to think when you're still holding out some hope for R and can't even picture your WW going PA with potential OM #2 or running off on you. You're still in a bit of denial if you don't realize that choosing limbo is also choosing to completely remove your ability to take control of your marriage and life for as long as you remain here and after infidelity, this is almost always a long, drawn out road to D covered in glass that you will have to inch over on your stomach. People who are here are aware that what they are doing is painful and it's a choice they are making because the trade off of staying in the M to enrich other aspects of their life is worth it and D would completely ruin it. Staying in a situation like this is the equivalent of slowing down a train crash when you are on the train so that you have more time to process and feel every terrible thing that's about to happen to you which is why when people in limbo like this do eventually D, they highly regret wasting time elongating their own pain for the exact same outcome. This doesn't mean you can't still try it out until you work on yourself enough to be able to either push through until your kids are old enough for you to feel comfortable with D or a D gets handed to you but don't delude yourself into thinking that you will remain contentedly numb for the rest of your life in limbo with no new DDays or without your WW deciding she can do better for herself than live in this hell alongside you. She may put on a brave face because the aftermath of DDay is still sort of fresh but her tolerance for unhappiness is lower than yours by default and her patience will run out. Shake yourself out of it and make a plan for your future.