We all miss the good times. Let’s face it, if we didn’t have them we wouldn’t have been stuck in the relationship.
However, it is unlikely you will see any change, especially if there is no diagnosis and no therapy taking place.
While I get that you would like to remain friends, you need to weigh up whether this would actually be healthy for you.

I’ve read some of your posts and you have said many times she believes she is always right, unfortunately if she thinks it’s all your fault you will unlikely be able to change that narrative.
As an example, I messaged my sister in law over a decade ago. I said I was worried about her sister. I was worried about her erratic driving in a fast car and I was worried she would end up dead in a ditch somewhere. My ex took that and turned it into I wanted her dead. She even reiterated that two weeks ago. I told her that isn’t what I had said and it wasn’t what I meant but she told me that I was wrong. That my own thoughts in my own head were wrong.

It isn’t silly, or tragic. It shows that you are a decent, healthy human being that has empathy. In time you will care less if you are blocked or not.

Thanks for  the responses.i guess the reason I thought of reaching out is I miss the good times, and some part of me hopes she might eventually change.  Which is silly I know. Plus I wanted to remain friends as I miss our friendship level interactions like phone chats etc. additionally I don’t like the idea that she thinks it’s all my fault and want to try to change that narrative. I guess I wanted to leave it as friends not the way it was left. I still care for her and worry for her as she doesn’t have a lot. She Had a shocking childhood and the rescuer side of me wants to see her ok too.. all a bit tragic eh%%?

My ex could easily catastrophize anything.  This is the opposite of normalcy bias* experts describe for normal people, and especially us.  One illustration is that if you drop a frog into near boiling water it will jump out.  But put it tepid water, you can turn up the heat and it will stay and get cooked.

*The normalcy bias describes our tendency to underestimate the possibility of disaster and believe that life will continue as normal, even in the face of significant threats or crises.

I often noticed that my ex would get upset or get upset worse when in the car.  I've come to compare it to home's privacy.  At home you're behind closed doors and out of the public view.  In the car you're confined with the other and out of the public view.

One difference is that at home you can leave, well, or at least try.  In vehicles you can stop but then the other can freak out even more.  One time I did pull over and stop, she then threatened to jump out and run across the interstate at night in the dark!

Max, I will mention here how our situations are similar in some ways but not in others, and how the legal aspects of divorce may impact how family court processes and "unwritten" policies seem to arrive at outcomes.  Even if you make no decisions now, it would be wise to seek some interviews or consultations of experienced family law attorneys.  Their legal advice will aid you in your interim decisions.  No need to go so far as to retain a lawyer until a need arises.

By the end of my contentious divorce I had been married 18 years and I paid 3 years alimony, two months for every year married.  Yours is only 12 years - sort of middling length thus far - so there also might be some alimony but not too long.  These days alimony is somewhat limited with the goal to help the disadvantaged ex to get settled in post-marriage life.

The major difference between us was that I had a very entitled spouse who at the end was extremely disparaging and possessive of "her" child.  So both BPD and NPD traits, though never diagnosed.  Apparently courts stay away from seeking diagnoses unless murder is involved, or it seems so with the high profile cases.  To summarize, they deal with (1) people as they are and (2) documentation and evidence while (3) moving the case along so slowly they're hoping the litigants will settle before they have to make decisions.

Though I separated when my child was 3yo, I will relate what happened then our child was 9yo, same as yours.

Divorce had ended 3 years before but she was still viewing me as a second-rate parent.  By then we had Shared Parenting, equal custody and equal time.  With the continuing conflict, I filed for custody and majority time.  Her alimony calc was about to end and her income was generously imputed at minimum wage.  Our GAL and the judge supported a deal where I did win custody but ex won with equal time unchanged... so she kept child support.  It was all about the art of the deal... masked as a settlement and not a court decision.

Our son was 9yo and didn't really know enough to not be influenced.  That's why minors don't attend court with the parents.  We eventually had a Guardian ad Litem (GAL - the children's lawyer).  Therapists, doctors and other professionals could share their input with the GAL without going into court and risking lawsuits or licensing complaints.

Conflict and entitled disparagement continued so I file again for the failed majority time.  This time the GAL was fed up with my ex.  ("Fool me once, shame on you. Fool me twice, shame on me.")  My ex's lawyer filed for court to have an "in camera" interview with our child, by then age 11.  Court allowed it.  (Usually kids are middle-school age or older.)  Magistrate and GAL spoke privately with him, no direct questions.  I'm told he spoke normally when discussing daddy, but lost eye contact when discussing mommy.  School also testified about problems with the mother.  The decision was majority time for me but only during the school year.  It felt to me that school got more credibility than I did, even though my experiences were throughout the year.  That finally deflated her entitlement a bit, we didn't go back to court again.

It would be wise to document the patterns you experience now since specific incidents (date, time, witnesses, details, etc) are important.  Time also is a factor, courts typically ignore most incidents older than 6 months before filing.  They call older incidents "legally stale" since if it was important enough you would have filed sooner, I guess.  Perhaps older incidents might be a basis to claim a pattern of behavior.

Beware of trying to be "too fair" or "too nice".  Court will be sure to more than protect your spouse.  Your task is to protect yourself and your parenting.  So don't Gift Away too much parenting.  My been there, done that advice is:  Get the best (least bad) court order, even the initial temporary one, because it will be an immense uphill struggle (think Sisyphus rolling that boulder up that mountain every day) to get it back.

It is wise to avoid the "YOU" word since that is so often triggering and pwBPD typically overreact.  It is better to make your boundary about yourself.  It still may not go well but at least we try our best.

I hadn't spoken with a sibling and neighbor for the past several years yet when I noticed he could save a few hundred dollars a year I felt impelled to cautiously inform him.  As expected, it didn't go well, he was snotty and critical.  Yet it was who I am.  I can't regret that.

This is the red flag I missed.  W has many previous partners or friends who went "NC".  I felt bad for her, because I have had that happen to me, too.  And for my W, there was also a list of people whom she had decided to go NC with. 

So my question regarding the pwBPD in your life - do they have a lifelong history of previous partners, friends, or family members who went NC?

Notwendy,
Thank you for your feedback. You have said what I fear the most: There is no nice way to tell this woman that her disclosures are inappropriate and she is going to take what I say badly. I believe this happened with the married man she is so obsessed with. She claims he came onto her, which does not seem likely. He is angry with both her and me. I know that I will likely become the new obsession as she complains to other people about me. I am lucky in that other people are aware of how she is, and have known me for many years, a lot longer than they have known her. I don't think there are many people that will fall for her smear campaign though some will, And there is not much I can do about that. For the future, I need to distance myself from this type of person. It is hard for me, as I remember when I was terribly emotionally dysregulated for many years.

Pook, you're the best.  Guess what?  I agree with you on both points.  I think that both can be true, even at the same time with BPD!  They feel they are trying really hard, and at the same time, they feel lousy because even though they're trying, deep down they know they falling short, and the shame is unbearable.  They are simultaneously unhappy about how hard and unfair life feels, and unhappy with feelings of inadequacy.  I think it all ties into the victim mindset and the learned helplessness.  

To your example of the failing business:  you were right to feel devastated.  Trust me, I ran a small business once too, and it is a lot of pressure having to completely "own" your own mistakes.  You can't even really take a break, because everything depends on you.  In the face of a huge setback, it's a natural reaction shut down, conserve energy and maybe temporarily lose hope.  But eventually, you took stock of the situation, and you decided to problem-solve, to resolve to work it out and fix the situation.  That is resilience and mental toughness--grit--perhaps mixed with vision, a little faith and optimism.  These are gifts that some people have, but I'd say that pwBPD are sorely lacking.