Starting with server version 9.6 and client version 8.12 have the ability to disable the overlay icon via policy. Under Enterprise > Policy Based Encryption > Show Advanced Settings there will be a policy named "Hide Overlay Icons". Enabling that will disable those from displaying across all your devices.
Currently there's no way to disable the system tray in a similar way. I've created a feature request and assigned it to our installer team to enable the switches we have for the child versions of the installers to be usable via the master installer.
Senior Principal Engineer, Support & Delivery Services
Dell Data Security
Need Immediate help? Please call DDS Support @ +1.877.459.7304 Ext. 4310039