Hi there.
I hope you are doing well, and have some more clarity on this since posting.
From what I understand, antipsychotics can have mood stabilizing benefits (similar to meds such as lamotrigine), as well as anti-anxiety effects. This would be better understood by your doctor, but that is what I’ve been told by my psychiatrist.
Antipsychotic meds can used to manage anxiety, mood fluctuations and even sleep problems.
Your doctor would be able to explain which options better suit particular symptom(s).
I would imagine that in BPD, these meds would be useful in managing mood changes, but treatment thereof would probably be best with both a doctor and an experienced therapist on board.
Best of luck,