It all starts with good ductwork designed for what you want to do
2 zone systems are a well traveled path by most hvac guys and there are a handful of ways to address the issue depending on disparities in loads or temps the options may be more limited . Bryant may have found another , or they may have found another way to market there ecm . dont know nor care because if the ductwork aint right you can put a super computer in the air handler and still have problems . and if the ductwork is right a relay and a PSC blower will run perfect .