This unit is not the right unit for zoning. It is a single stage system. I recommend a variable speed system. Plenum is not sealed. Losing a lot of air out of the coil/supply drop. Most of the supplies are to close to the end of the trunk. This cuts airflow cause there’s no area to build up. All the flex in the attic is R4.2 which isn’t per code. This insulation isn’t rated high enough for an attic. It’s picking up a lot of heat before it gets to the vents. There is one 10in flex feeding 3 runs for workout room. This isn’t big enough. Zones are opting and closing like they are supposed to but we are losing about 25% of cooling because of duct not being sealed and the insulation not being adequate. To properly fix this issue I recommend replacing the system with a variable speed system with communicating dampers and flex that is up to code. Will quote to replace duct and unit.