I’m not intimately familiar with the concept of ‘smart zoning’, but I believe the idea from @h0ckeysk8er is that you could create rules to zone things however you see fit. For example, if you had temperature sensors that you wanted to react to and adjust your vents (alongside thermostat setpoints), you could create rules that use those temperate values and take action on your vents accordingly.
I am using Sharptools rules to manage my 3 Keen vents, all downstairs.
I also have an Ecobee thermostat with 3 addl sensors, one downstairs, two upstairs. I set up an Ecobee schedule called Sleep which comes on at 9:30 pm and ends at 7am the next day. Sleep schedule only includes my upstairs sensors which is where the bedrooms are.
I then set up a rule in Sharptools to close the downstairs vents at 9:30 pm and open them again at 7 am. That creates some basic zoning.
Sharptools gets lots of info about the thermostat that you can create rules around (set points, fan modes …) but unfortunately Ecobee did not expose the schedule name, so I am stuck with hard coded time triggers.