- Navigate to
/Library/LaunchAgents/. - Edit
com.razer.rzupdater.plist. - Change
<false/>inonDemandto<true/>.
This will disable the menu bar item, and the startup of the Synapse app while still loading the engine!
Credits: http://www.mac-forums.com/forums/os-x-apps-games/273786-razer-synapse-2-0-a.html
I just did it on High Sierra, still works.