Hmm, well I disengaged a year or two after I met my DH - so in 2003 or 2004 - making it at least 16 yrs ago.  I didn't realise what I was doing had a name at the time - I was just stepping back in order to preserve what was left of my sanity.  Bear in mind that in 1999 I'd had a colossal breakdown and been hospitalised. Then left my ExH of 24 yrs and started seeing DH.  His ExW made our lives hell and she decided to PAS the SDs against me before she'd even met me.  I don't take it personally - she's a twunt and would have done the same to anyone. Nothing that has happened since has caused me to question or regret my decision to disengage.  

It seems like forever. Ive been with Dh for 5.5 years. SD20 Feral Forger left the home 2.5 years ago.

I had disengaged about 3.5 years ago, when she had verbally abused me.

I feel at peace and cannot imagine ever living with her ever ever again in this lifetime, especially after hearing about the absolute chaos and horribleness Munchkin SD13 had to witness at Toxic Troll's house.

I disengaged whenever Spawn was 16 getting ready to turn 17, so almost 6 years.  Once I disengaged my anxiety levels began to drop.  I began to focus more on myself and my children and I worried less and less about what Spawn, Meth Mouth and Grand Hag we're going to do.

With the return of Spawn into DHs life I admit I have had more anxiety lately and have felt the same desolation and despair I used to feel when Spawn and Meth Mouth were controlling our lives.  I have had to tell DH very firmly what my boundaries are and to let him know that he cannot in the future try to guilt me back into a relationship with his taint if I do not want it. 

I disengaged about 5 years ago. Me disengaging was the catalyst for Death of the Disney Dad and DH started to parent again without fear.

Disengagement and BioHo's gradual ramping up of the drunken narc craziness has actually improved my relationshiip with the skids over the years. Even SD23 has finally seen the light. It's... kinda weird.

DH and I have been disengaged from YSD for over 14 years, ever since she packed up and took off while we were at work. She even stole the gifts for her that were under the Christmas tree.

I disengaged from OSD 8.5 years ago. DH was not happy about it, but soon got fed up with her because I wasn't acting as a buffer anymore. I don't think he ever really knew OSD, as I handled everything for him. She is a narcissist, undiagnosed but I'm not throwing that term around lightly. Her extinction burst lasted for a few months, sending her father letters telling him she'd done nothing wrong, returning our house key, and escalating trying to regain control. (Her self righteousness didn't extend to repaying any of the $$ we loaned her, though.) When that didn't work, she just deleted us. Such a gift!

Disengaging from OSD led to a major personal growth spurt for me, and I had to face up to some scary truths I had been avoiding for years: that my perception of the dysfunction was valid; that pretending everything was okay was never going to make it okay; and that I'd wasted my love and time on people who didn't care about me and never would.

I'd been doormatting and trying to fit in with DH's dysfunctional family for almost two decades at that point, and his sisters openly turned on me. I had to get real, and start dealing with What Is rather than go along with the pretense that was a regular part of DH's family dynamic.

Hard stuff, but ultimately absolutely worth it. And my marriage is stronger than ever, because we now deal in truth and are living authentically.

Process. Like any change, it takes time to adjust your thinking. I always sensed she wasn't as she presented, and her actions previous to the "main event" my  divination or intuition of what was to come was spot on.

All this hugger-mugger communicartion between my DH and SD was bound to come to light sooner or later.

At first I was fllummoxed and in shock and I tried to figure out "WHY" anyone would behave as SD did. Especially when there were many other ways she could've chosen to handle the situation, rather than an hour long rant. I wanted an apology, and didn't understand why she profusely apologized to DH, but not me, when I took the brunt of her tantrum as she verbally pistol whipped me.

Then I moved to a place of acceptance, not in a sense of being ok with it, but it was more like "it is what it is" but I don't have to subject myself to this toxic mess.

After that (about 3 weeks in)  I saw it for what it was and decided an apology was not even on my radar. That ship sailed long ago, and it wouldn't be sincere anyway. It would just be another way for her to work her way back into our lives and to continue manipulating her father further. I made up my mind there really wasn't anything she could do to rectify or justify her actions and lack of class that would make me want to be in relationship with her on ANY LEVEL. I blocked her in every way possible from my life.

Later I was grateful for her meltdown, and that it happened in front of DH so he could see her for her authentic self. He would never have believed it if I had tried to recreate it through my perspective. As strange as it seems, that was my emancipation from her and her narcissistic dysfunction.This vicissitude was exactly what was needed, the bridge to get from THERE to HERE. Now I see that situation, as horrible as it was, actually worked to my advantage. I haven't had to put  my eyes on her in almost 2 years, and while it has been a struggle to move through the phases and stages of this journey, I WILL NEVER GO BACK, OR WELCOME HER BS INTO MY LIFE OR MARRIAGE EVER AGAIN. 

My DH is not the type to take a stand for anyone or anything, so while she turned red and the veins popped out on her neck and she screamed at me violently just inches from my face, he just stood there next to me saying nothing and doing nothing. In my opinion silence is affirmation. The good news is, he is WITH ME EVERY DAY, DAY IN AND DAY OUT. He is NOT with her, so while he wouldn't take a stand for me, us or our marriage, she is also seeing that ddaaaadddeee will not divorce or otherwise abandon his wife FOR HER.

Silence is golden, in more ways than one.

It's been going on 4 years for me and I feel so much happier in my marriage.  It's been almost 2 years for my DH and OSD27 is a mess and mimi BM. I disengaged for my sanity and got to a point where I didn't care and even encouraged DH's relationship with OSD but he opted out because I set my boundaries and was NOT willing to be a participant any longer and he hated having to deal with SD's never ending drama on his own. I feel so relieved and don't care what she thinks or feels and will avoid her at all costs. My DH'S family, suddenly after 3 years (except MIL and she's skating on thin ice with DH if I'm being honest) even tries to avoid her because "she's bougy" but i've even disengaged from them because 'where were they when I was hurting and feeling undefeated trying to make me the evil SM'... all in all I'm done and my DH can compartmentalize his relationships with his family of origin and me and our kids and he's clearly chose the latter. They can figure it out on their own. I chose peace and happiness! And he chose love, support and stress free!

So I'm at 3 weeks of disengagement from SD31. Admittedly I and enjoying having less angst around home with just DH and myself; however I am having trouble getting past the guilt, since I am the one who caused the rift. 
In an uncharacteristic move, I called SD31 and told her off about how she had disrespected my daughter (including her education, her chosen career and her colleagues), all wrapped up in her conspiracy theory/5G/antivax BS. 
SD31 cried and fussed, as expected, and told her dad how I put her down, treated her like a child, and insulted her. Nope, I didn't. But I did tell her off and she has been giving me the silent treatment (her mother's MO) since.  

I'm feeling very sad and guilty that my actions caused strain in the so-called 'family' (our kids are all adults). DH is sad but realistic - he knew it was coming (hmm... why didn't we talk about this before I reached a breaking point?!). He says she has sh*t to work out  in regards to her relationship with her BM, which she is now taking out on me.

Maybe I deserve the silent treatment. Some days I am glad of it; still, I hate that my rash behaviour will have long reaching consequences.