For the 10 years that we have owned our Windstar there has been disagreement about how to efficiently heat/cool the van when we first get in. I say: turn on front vents AND the back vents to quickly heat/cool the entire interior. My husband says: turn on the front vents and let the heat/cool air work its way to the back.
Your husband must know more than the Ford engineers. Afterall, they’re ones that spent all that time money in testing to determine what is the most efficient way to heat/cool the interior of the vehicle. If the back vents didn’t have an effect, they wouldn’t be there.