I have 2 Garmin devices recording similar data (in my case an Edge 810 and a Fenix 3). Since buying my Fenix, I never synced the Edge again, worried it would create duplicate entries in my connect-overview.
As a side-effect, I also no longer install updates on the Edge.
So, in short: how do I only sync activities from the Fenix, while allowing both devices to get updates?