I think that Standing is an ‘abnormal’ reaction....in the sense of being an uncommon and counter-intuitive response to the events that most of us experience. That doesn't make it wrong, but it does mean I think that the choice to stand probably requires accepting that it is an uncommon choice so a path less well-trodden maybe?
I also suspect that it is too simplistic to define it by whether folks move on with other relationships or not. There are quite a few of us who are not in new relationships but who would no longer define ourselves as Standing...but perhaps living in a way that looks like we are. And perhaps some in new relationships with a glimmer of Standing-ish that leaves a metaphorical door open for a spouse they loved but unsure if they will ever be seen again. Or some that consider a new marriage a ‘forced’ end to a Stand. Or some who live within the form of still being married if not the function who Stand as some kind of ‘home’ for a person they see as ‘ill’ in some way who they hope will recover even if the marriage will not. Some Stand bc of faith beliefs, some bc they believe a bit of the spouse they knew exists behind the chaos, some bc it’s the only way they see to hold a fractured family together in some kind of connection, some bc they see RCR as a guide who knows things they don’t, some bc they just don’t know what else to do right now.......and lots more reasons probably.....
As the saying goes, it’s complicated 
Which is why it’s probably helpful for HS to occasionally recircle round to a discussion about it, as I think happens. Helps people figure out what Standing means - or doesn’t - to them. And if their choice or the way they live that choice more accurately perhaps is healthy and constructive for them or not at a given point.
And I think it can hurt all of us, regardless of our choices, if we feel judged as ‘less than’ bc of them.
I have a sneaky suspicion that most LBS are too battered and too confused to really make a really ‘examined’ choice about Standing for maybe a couple of years. We come to HS probably bc it is a default one for a range of reasons. Like a hammer who only sees nails lol. And that is the time when it is often very hard to make wise healthy choices, isn’t it? When we are vulnerable to dysfunctional choices bc it is so hard to find our footing or work out what we are dealing with, or think we are dealing with. Bc we want so much to believe that there is a predictable map or a process or things we can do or tips or tricks or a POV to change the situation we find ourselves in. To have hope, to reduce our pain.
I also have a sneaky suspicion that there are factors that make Standing more or less sustainable if we choose to do it past that point. And some of those factors are not necessarily in our gift or control. And not all of those factors are about what we think or feel or believe about MLC or Standing or Life.....some of them are about resources or bandwidth....and some of them are perhaps about different ways to ‘do’ Standing as opposed to ‘be’ Standing? I wonder if it might even be useful to start a discussion topic on different ways that experienced folks have found to ‘do’ Standing in healthy non-dysfunctional ways (as opposed to whether or not one should be a Stander) bc I’d imagine that Standing is also something one learns how to do well through a bit of trial and error 
Thought I would bring this over to my thread rather than chomping up space on Marvin’s thread

With hindsight, I now think Standing had three separate bits for me. Standing for what marriage meant to me, Standing for my marriage relationship as i’d experienced it and Standing for my then h’s ‘recovery’ to someone more recognisably healthy.
And they were much more separate processes than I realised. Required different things of me. Different costs. Different timescales.
I should say, in the interests of honest disclosure, that I am not Standing for any of those things now. I have accepted that they either no longer exist or that they are beyond my pay grade or influence.

Standing for what marriage meant to me was actually the easiest one and required very few monkeys in its creation lol. I married once for life and would not choose to remarry. I have never needed to chew on that. And marriage meant, to me, choosing to treat my then h with respect and kindness as much as I could. That was at the heart to me of the promise I had made so many years earlier....to act with care, I suppose....not to care for, but to care about. That kept me from reacting in some ways that would have felt good for 30 mins but not longer term

....but it also took me to respecting his right to carve his own path and choices and consequences. Even if I didn’t like them or agree with them. Actually even if they made no sense to me at all.
Standing for my relationship was more painful and took longer. Bc tbh it was dead in the water long before I wanted to accept it was dead. The very thing I had treasured most about it had been irrecoverably imho killed off by my then h’s behaviour. I simply couldn’t see it, or him, or us in the way that I had done. Nothing to do with love or hope or anything I felt....it just WAS a basic truth, or so it seemed to me. I could not have it back, not with my h and not with someone else bc it was a co-creation. I stopped Standing for that after about 18 months or so....literally bc I had a dream in June 2017 of a conversation with my then h. I woke up and I just knew.
Two down then

The third was the most painful and took the longest time of all

I suspect tbh that this was less about love and more about attachment, the feeling that I had any kind of part to play in his life or he in mine.
It required me to wrestle rather a lot with who I thought my h was/is and what felt real and what did not...bc that was the path my brain seemed to need to figure out what I thought happened and therefore what I thought could happen. On balance, while I am not as sure-footed about it as Marvin seems to be, I do think my then h had some kind of profound fracturing. Not just bc of my experience of it but bc objectively he was under psychiatric care for a long time and bc of all the things which were nothing to do with me or our marriage. But it also took me to a place of accepting all the things I simply don’t know vs the the things I thing I do. And with a vanisher who essentially ghosted his way out, there is so much I don’t know

I think, slowly (ha ha very slowly) I got to the point where it mostly seemed a bit silly and rather arrogant and disrespectful to Stand for a person who no longer existed or wanted to be that person if that makes sense? I think I had to recover from some of my own PTSD enough to find my own footing that I could let go of that attachment as much as I have done. That my h became a chapter not my story, I suppose. So probably didn’t get here until idk, about 3-4 years

...and NC since 2019 helped that be a real thing.
So, three out of three

Easier to do with a vanisher and no kids or ongoing connections perhaps.
And it would seem as weird to me now to think that I have any part to play in his life or recovery as it would if he popped up thinking he had a role to play in mine now or in my recovery from PTSD

That was the last bit of letting go, I think, and it took me YEARS

The only bit of residue I think I might have from the last bit of Standing is that I hope that my xh ‘recovers’ (whatever that means to him), I do not wish him harm or unhappiness and I am occasionally touched by gratitude for the memories I have (Although they have faded a lot with time). Tbh I see it as a kind of death really more and more...I think that is how I live mostly, like I was widowed. (No idea if that seems nuts or not lol)...and acceptance of that was the deal changer for me both in my own life and in my sense of attachment. He was very important to me, ‘unique au monde’ as I have said before....and now tbh he is of no significance at all in my life. In my memories, in my path to here, yes....but in my life now, no. Might that change? Well, idk....it has never really been put to the test....I have no idea how I would respond if it was, if he reappeared in some form as Marvin’s wife/friend has done or as I know other LBS have experienced years later. But I suppose the last bit of Standing Down, for me, was that I feel no need to think about it or do or wish anything to stir that particular pot. I am probably rather grateful that I don’t need to and grateful that I was married for a good while to someone who I enjoyed so much. But I did well to survive the s&itstorm bc I did not think I would and I cannot conceive of even wanting to dip a toe in someone else’s crisis again

I share this bc, with the gift of hindsight, I can see that Standing was more complicated than I thought it was at first. And, if only for that reason, it makes sense to me that it is not so straightforward to judge how others figure it out, that it is a very personal and evolving process. I hope it helps others a bit further down the path, like me, to figure out what is healthy and appropriate for them. And of course my experience is not necessarily yours, is it?
I think, again with hindsight, as Acorn said somewhere, the dysfunction of Standing - or how I did it - was when I conflated my then h’s path with our relationship. My stage two, I suppose.....I hurt myself more there and let myself get more damaged there bc I had expectations and wants I suppose....I was still in the ‘game’ in some way, like a piece on an incomprehensible chessboard with random WTF rules lol. Which is funny really bc we say so often - and I thought I got it - that a spouse in crisis is about them not the relationship. But I don’t think I really got that until I let go of the feeling that we had a role to play still in each other’s lives. Ironic really bc we LBS are bewildered by the relationship being treated as the ‘problem’ by the MLCer....but if i’m honest, I did the opposite for a goodly while and saw the restored relationship with a h I recognised as the ‘solution’. Now, of course, it seems easier to see - even with a remarried vanisher - that neither are true

But that was the spot where Standing in the way I saw it then was unhealthy for me bc I took on a lot of damage bc of my own mindset I suppose.
It occurs to me now that Standing....and then slowly standing down...was rather like removing bricks from my previous wall. Maybe it was necessary in order to get to the point when one can even start building a new one.
Perhaps working out what role you each play - or want to, or not - in each other’s lives is what happens in reconnection or reconciliation? Idk, not something I have experienced.
Ah well, reflections from the other side fwiw

Toast, tea and allotment for me today. (And it is very nice that now I do not talk to ghosts while working on my allotment as I once did....just me, young growing things, muddy fingers and the sound of birdsong

)