I think you'll find that there is redundancy built into the panel. If the Airbus panel is like the 767 panel, (inside) there are separate power supplies (each of the ILS/MMR receivers can power the panel... and the receivers have separate power supplies), there are separate processors and, most likely, the switches are "ganged" (multiple contacts).
The only way you're going to get into trouble is if one of the knobs falls off
Rgds.
NSEU