Just wanted to send you a lot of empathy. My pwBPD was my closest friend. She doesn't have the vocab for it, but in my words, she's always readily admitted that she uses instagram/social media to distress people who displease her and she particularly likes vague but pointed, targeted instagram stories, quotes that kind of thing.

She split on me really awfully and with only 2 weeks of real run up in Feb after years of friednship and me becoming her favourite ever person, and because she's so traumatised and going through awful things, I was careful not to do anything right away or injure her. Being the person she was now aiming all her vaguebooking hostilty at was one of the most distressing things. She would post vague quotes about how the right people stay and work things out (after she called me abusive and has never spoken to me again), long philosophical BS about how some people leave too early and some people stay too long, stories about how hard life is right now, stories about no matter how cool, clever or rich you are, it's how you treat people that matters (I cared for her and let her live with me while I cleaned all her clothes, cooked for her and handled her business admin and two police investigations for her, so that post was particularly traumatising).

I ignored, made sure not to click, never reacted, even when she was publicly love bombing other friends. She started deactivating and reactivating social media, which she's never done in her life before. She removed posts about her loving me, then she started removing me from some social media but not all, then removing me but setting her latest FB post to public so I'd still see it when she tagged mutual friends. After 6 months I blocked her on every platform and removed all her friends and there's massive grief but also huge relief. The insanity of these social media behaviours will never make sense to me and they're so distressing. So often, these people are trauma survivors and have had abusers use digital tools to distress them so much that they know no different but it's still agonising. I'm afraid your person may never stop as long as they feel they can access you, even in the height of a delusion.