Yes! A single flow meter can be wired to a single controller to measure flow rates for up to 36 zones, whether it be a combination of master controllers or expansion modules.
All the controllers pictured below are 12-zone controllers. This is because expansion modules only work with 12-zone controllers. They are not available for use with the 6-zone controller.
If you plan to use multiple master controllers with maximum expansion modules, we recommend getting a flow meter for each master controller (physically wired to each master controller) and assigning it accordingly to the linked expansion modules zones. This will create less confusion regarding which flow meter is measuring what. Meanwhile, all controllers can be on the same account for easier management.
IMPORTANT This setup has been proven to work, however, please note it is not a feature that is supported.