Changing the module will do nothing. You can set the dual option in any module and it would work as far as settings go. The problem is that the HVAC units are not made with the correct door in them to split the sides. This means they do not have the correct Servo to change that door or the wiring to the servo.
You have to replace unit or add the door which would require removal of the dash and disassembly of the HVAC system. If it is that important to you than yes it could be done but it is a major project.