Using the ERB Secure Browser turns off the screenshot function (Shift - Command -4 - partial screen and Shift-Command-3 - whole screen)
It does NOT turn off Shift-Command-5 - which allows you to do screenshots and record screen activity.
The ERB Secure Browser also turns off the keyboard shortcut to Spotlight search.
Apple Menu (top left) > System Settings > search "screenshot"
Click on Keyboard shortcuts on search results on the left
Click the Keyboard Shortcuts button
Click Screenshots on the left
Check all the boxes
Click Spotlight.
Check box next to Show Spotlight Search
Click Done