How do I restrict a novice user from installing configuration profiles on their devices?
As this key is a ‘supervised only’ key, the device must be in supervision for this key to be functional, otherwise it will have no effect.

Once your device is supervised, you can create and install a profile with the key set. You can create such a profile with Apple Configurator. Choose Restrictions as the payload, then under Functionality, uncheck ‘Allow installing configuration profiles’.



Complete the mandatory General payload, then save this profile and install it on your now-supervised device for the payload to function.