Missed the point. If that operation is so critical, give me a workplace owned device to deal with it. My employer is not getting superuser access to my personal devices.
they do not need super-user permissions. That would imply that the phone has to be rooted. over-coming certain settings that apply to regular apps? sure. but that's a very android/iOS specific feature-set that is exposed to all app developers.
They do not need superuser, they can just request the permission to bypass DND. I believe apps can't tell if you gave them the permission or not, so there is no way to "force" users into this.