For other EZxx devices, when you establish a link to a particular input or output, that suppresses the Broadcast message for that input or output. Would expect the same thing here but cannot confirm that with direct experience.
The Insteon Traffic tab of the SHN Utility is not a generalized Insteon traffic trace. It shows only specific commands issued by the Utility and the response to those commands.
You mentioned that the ISY established responder links for each of the Zones when the EZFlora was initially added to the ISY. Are those responder link records displayed by the Utility under Manage Device Links tab, Display Existing Link Records button?