i am new owner of fenix (still learning ..) - i would like set Express for automatic offer of new version of fw only, NOT directly export fw to device. I don't see any checkbox for this setting.
I am happy to answer questions about your fenix 3 HR and Garmin Express. Unfortunately, there is no setting in Garmin Express to prevent it from sending a firmware update to this device when it syncs. However, on the watch you can choose "Remind Me" to postpone the update or "Dismiss" to ignore it.
We are sorry for the inconvenience this may cause.