ducted or free return air in foamed attic

I live in central Texas an am building a house. The roof as well as the walls will have foam insulation. My A/C contractor has two options for return air. One, to have grills in the ceiling to return the air to the air handler and two, to duct the return air. My concern with the grills is noise transmission between rooms. The contractor also says that this method will keep the attic within 10 deg of the home and reduce humidity. The ducted system should also make the attic cool but not as much. I worry in a humid climate that the attic will be humid. Would it be possible to have the contractor put a discharge vent in the attic to help remove humidity? Any comments or corrections to my assumptions would be greatly appreciated.
Thank you in advance

source https://hvac-talk.com/vbb/threads/2242968-ducted-or-free-return-air-in-foamed-attic?goto=newpost