Designer personalities are possessed by people who are creative, and have the talent or skill of being innovative. According to the big five personality theory, people who are creative have personality qualities which are helpful in making something new, they take the initiative to create new things.
Even when it will be possible to 'create' a designer personality, it will be highly unlikely that an absolutely desired designed personality will be brought into existence, as we have not fully known the potential unpredictability within our species.
Advantage of designer personality can be this that it will be controllable, since it is programmed and predictable.
Disadvantage: race in designing humans and in engineering humans.
No personality theory will take away from humans the nature of personality formation being unique. Hence, creative aspect is present, no matter what the uniform treatment of the evolution and environmental factors might be.
According to the genomic project of human engineering and the ethical debate of creating selected human prototypes, by manipulating genes and environment, ...
personality theory: designing - short answer