Normally, CB's are not employed in the usual way.
Having read PJ2's post and some of the comments therein I am more than ever convinced that electronic control and actuation of some systems is not always the way to go. If the CB's mentioned control only a computer, which presumably controls the associated switching and relays involved with the Windshield Heating System, then what happens when a relay malfunctions and continues to allow power to the system, regardless of what the computer tells it to do? Having had the experience of a Windshield Heat transformer catch fire behind a cockpit panel I know that having the power supply CB accessible in the cockpit was very helpful. Pull the CB for the power and, usually, the problem is solved.