This is a belief and a logical conclusion/inference based on mostly beliefs, a theory that fits basic assumptions, and difficult to find strong supporting evidence for.

Basically, I believe that integrating BP into your personality is healthier than not doing that. I see BP as a form of disintegration, dissociation. The allowances afforded by a borderline personality create greater flexibility, so that your BP is more controlled and reintegrating instead of disintegrating. You break up into pieces less. I think you should embrace such personality (and change/improve it).

To me, it's rather obvious. People don't just develop a personality that is disadvantageous. That it helps in some way is very likely. That is exists seemingly on it's own, seemingly having only disadvantages makes no sense to me. It makes it likely there is a problem it neutralises so as to become subclinical BP (or subclinical unipolar depression).

Edit:
The dissociation would be one of the rational and emotional/intuitive self: an inability to (correctly) rationalise one's emotions. It could lead to (more) extreme disintegration: depression and mania.