With BPD, it's normally the people (mostly Women) aren't diagnosed when they have it and misdiagnosed when they don't. I haven't looked at it super recently, but medications actually do nothing useful but maybe keeping a Rage Cycle from expanding. (Though those medications normally come at severe cost in everything else.) But the Face Blindness is a repeatable, testable aspect.I mean, sometimes people can recover from it as they get older, right? I had heard that it gets much better for women in particular after they go through menopause and whatnot, but I'm no pyschiatrist.
EDIT: Ok, I'm going down an internet rabbit-hole on this BPD misdiagnosis stuff right now and I see what you mean
That said, Cluster B disorders are what we normally just call sociopathy. Just different flavors. The real reason they get out of control is the lack of personal accountability. That's what makes them spiral. The sociopathic attention seeking that Doki hasn't shown is why I'd question the diagnosis, but the Face Blindness is really just a result not the cause. It can happen for other reasons.