My main supply plenum splits into 3 trunk ducts... one for each level of the house. This is not common, but something I requested when we had the house built over 10 years ago. I recently added motorized Honeywell dampers to each duct and control them with custom rules based on where I want air to go. A Zooz ZEN16 is used for the "smarts." Everything is hardwired and powered by a 24VAC transformer. It has worked great this winter and I'm looking forward to seeing how the summer season goes.
If you have access to your ducts, you should be able to do something similar. There is also a great HVAC zoning app that can help. Includes options for dampers, booster fans, etc. The documentation is great and has some really helpful info for avoiding things like freezing your AC coils and the like. I really wanted to use it but my ecobee thermostat doesn't play nice with the app.
