That makes sense. The therapist is going to focus on you- because you are the client. He wouldn't be able to make an assessment of her as he hasn't seen or met her.
So perhaps he can't assume she has BPD but I think/hope he'd be able to help you with your side of things.
As to what to do next to attempt to reach out- I don't think there's a "BPD approach"- they are still individuals. I think you have sent messages/gifts already and she hasn't responded. Of the ideas you mentioned- if you are already in town, you could ask her to meet you for coffee just to talk- if she doesn't want to do that, then you have tried.
If you communicate with her, I wouldn't tell her how miserable you are or that you disagree with how she's going about this- this is putting your feelings out there for her and pwBPD have difficulty with their own feelings, and so it's not likely to get you the response you would wish for.
See? It was not so complicated to give me a good advice, as you did and many others did previously.
Even tho you were discouraging me to reach out or something, your advice were valuable and on point.
My therapist was just trying to dismantle the BPD thing entirely, even tho my ex mentioned the issue, saying that another therapist told her she might have it. And that's the only reason why I started digging into this matter and everything magically made finally sense. So I don't think he is doing a great job for his client, by invalidating entirely my hypothesis, which is based on two facts and many elements that concour in the BPD behavior and my ex behavior. Even tho you won't accept that we can assume she has BPD, which is fine, he should just listen and take into consideration her behavior which is factual, and not dismissing what I'm saying.
Anyway thanks again, I'll follow your advice actually I'm just gonna wait till next month and cross my fingers!
If she doesn't reply or react well, I might just send her stuff back for Christmas with a gift I wanted to give her and a letter and I will never text her anymore if she don't wan't to communicate with me.
What do you think?