Good to see you back here -- you're always welcome

The course of my life has been weirdly immersed in people with BPD and related disorders. My adoptive mother, who raised me from infancy, had BPD. My ex and her son also. And that's not too surprising - people tend to get together with romantic partners resembling their early caregivers.
Yes, that seems to be common, that we're drawn towards relational dynamics that feel familiar to us. In a way, that's neither a good thing nor a bad thing, but it is a thing to be aware of.
My best friend in high school has a mother with what is probably diagnosable and low functioning BPD, though she sort of held it together publicly back then. I had no idea about her disorder because my friend lived with her dad, and I never met her mom until much later (post college). So it wasn't like I met my friend, then met her mom, and thought, wow, her mom just feels so familiar to me, I'll be friends with this girl! I think it's much more subtle than that.
Another friend I've had for decades comes from a family where neither parent was very emotionally expressive and they didn't really talk to each other about feelings. That also felt familiar and comfortable to me, and it's something we're only really realizing and airing now.
That doesn't mean the friendships aren't "real" or that "it's just based on dysfunction." I love my friends! And, it's possible that we "vibed" for reasons beyond what we knew at the time.
Of course, in your case, when it comes to supervisors/coworkers, you do have the option of dialing back the connection/interaction to the bare minimum to function for work.
And I've come to realize that my current supervisor at work clearly qualifies for a diagnosis of HPD. I've been trying to compensate for her shortcomings.
Are you still doing that, or are you looking for different ways to navigate this?
I was in denial about my ex's BPD until a therapist pointed it out at the end of the relationship.
It can help to get that neutral perspective on our choices and tendencies. As you move forward with the goal of not just declining to get in a relationship with a disordered person, but, likely, choosing to get in relationships with healthy people, are you still seeing that therapist?
After we broke up, my ex tried a DBT group and disliked it, dropping out after several months. Then I found a Schema Therapist for her, and she's been seeing her since. The other day, my stepson went to his first appointment with a Schema Therapist/addiction counselor I found for him, and he intends to keep going; I'm glad about that.
Sounds like some bittersweet good news. Of course you wish it could've worked out before this, and I also hear what you're saying, that you're glad they're both committed to and engaged with meaningful support. I wish them the best in their healing, and that they can both connect with and trust their therapists.
And life goes on.
it sure does... with or without our cooperation

Reminds me of what a retired staff member had as his profile quotation: "Let go or be dragged"
If I'm remembering correctly, you've enjoyed doing outdoor pursuits? Are you able to keep up with being outside/being in nature?