The safe mode on your Android devices, can be restricted via a policy through Hexnode. Upon opening a policy and navigating to Android -> Restrictions, you will find an option titled “Safe Mode”, under the area “Allow Device Functionality”.
This option can be disabled, if your target is to block users from turning ON the safe mode.
This feature shall work either by enrolling your devices in Android Enterprise as a “Device Owner” or by enrolling devices which are Samsung Knox compatible.
If your devices cannot be enrolled in the above-mentioned ways, this feature will then work in devices which are enrolled in the legacy Android way, but only on those devices whose Android version is below Android 7.