These are clinical standards for self-absorption and toxic personality traits. In their relationships, cluster-Bs select for supplicants who will love them despite their toxicity. What you're saying about the memoir is consistent with this.
Her mental health conditions aren't a reason to disregard everything she says, but she is providing social and interpersonal advice here, in a way that is likely to encode the dysfunctional schema and disordered thinking she suffered from in life.
For an opinion piece that is about how to empathize with other people, I think it is relevant information that the author probably had a clinical impairment in their own ability to empathize with and understand others.
and yes, one of my best friends has BPD and i dated somebody who had it, and listening to them and their subjective experience and tips on how to communicate with them was the best thing i could ever do.
I'm interested in how you concluded the advice was so beneficial. Was it a reduction in conflict and fewer emotional outbursts from your BPD partner? A feeling that you're better able to soothe them and manage their feelings?
Being conditioned by your BPD partner to excessively validate and center them is not the same as empathy.
edit: it appears we're talking past each other. i like this piece of writing and you don't. that's fine. do you have any suggestions for me to read about how to listen, written by one of your favorite writers or poets? this will help me better understand how to listen to you.