The question seems to be whether your ex will come back to you.
BPD has a spectrum, relationship dynamics have a role, there are so many variables in play.
In the book Buddha and the Borderline, the author leaves one toxic relationship and stays away. Later, in a healthier (though still difficult) relationship, she leaves and comes back. Eventually, after going through DBT, she ends it for good.
That's the example that came to mind when I saw your post. Part of the author's journey through her relationships is contingent on her own growth and coming to grips with what is best for her.
I made it clear to her the last time we spoke that I wasn't interested in seeing anyone else, I only wanted her and I never wanted to break up I just wanted to take things slower.
This is JADEing (justify, argue, defend, explain). It typically does not work with BPD sufferers. When she is in a state of heightened emotional arousal, it's best to acknowledge her emotions so they do not keep escalating. Usually, when we don't feel heard, we continue to say or do the same thing until we feel heard. With BPD, feeling heard is kinda job number one.
Defending your actions only keeps the focus on your actions, and defending is another way of telling someone they're wrong. To someone with BPD, the message comes across as, "You are wrong to feel the way you do." Which is the same as saying, "You are wrong to be who you are." They tend to feel that way just being in the world, and are always on high alert for signs that it's true.
Her feelings are likely very intense right now and she is trying to regain control over herself, which is about her, not you. If you two do reconnect at some point, the odds of things improving will increase if you feel strong enough to validate her when your own emotions are heightened.
It takes a lot of radical acceptance and centering to not be emotionally injured ourselves, so that we can be supportive and empathetic when our BPD loved ones need that from us.