It's not easy. Someone with BPD carries a lot of shame, so seeing faults in themselves is a big no no, it can trigger a spiral shame and lead them to self harm or other destructive behaviors.
I definitely have empathy and sympathy for them despite them being an economic superior to me but the stark absence of any authenticity offends me on a level I could never sustain a friendship or even likely aquaintanceship (whatever that means) with them.