Yes. I agree. Do not let common sense, reasoning, and logic get in the way of one's dream of appearing cool.
If it were me, and I wanted to have better exhaust flow, I would try to repair the modified original manifold to function as a dual exhaust.
There is a real benefit to the original design of the heat flapper box during cold operation, as well as for some heating of the intake after reaching full operating temperature. Neither of these functions can be duplicated with pipes coming from a header to the intake.
