For reference, I have CPTSD, my brother has BPD. We were both abused and neglected by chaotic, addict, middle class mother and step Dad, our father was absent.
I don’t have a criminal record, because I don’t commit that sort of behaviour, he spent most of his 20s being arrested with three brief stints in prison.
His relationships have all been intense, turbulent and short. He has remained single for a decade (after his last stint in prison when he got a place in supported living, had intensive therapy and has changed himself as much as someone with BPD can), because relationships (amongst other things) are huge triggers for behavioural changes.
I have a PhD, he has a handful of GCSEs at a Grade D.
I have children, he (thankfully/that he’s aware of!) does not.
Crucially, in my opinion, he stayed in regular contact with our parents until the third stint in prison, when he went and has remained NC. I stayed out of our home as much as possible during GCSE/A Levels, went to Uni as far away as possible, was NC by my first Christmas away and haven’t spoken to them since.
Having witnessed my brothers life, there is no chance I would date someone with BPD or anything worse than a “basic” mental health issue.