.
One thing to consider is that if the cable breaks, the carbs will always return to idle.
If a control rod passing through the shroud ever jammed, the throttle could get stuck open . I think that would have me worrying more than a cable breaking.
Also, if the cable breaks, it's likely to happen where it exits the shroud, near the hexbar, as that's where it rubs the side of the tube the most. But that area is easy to inspect for fraying. Some light lube (like Tri-Flow) at that spot probably isn't a bad idea, either.
Cleaning and lubing all of the 'wear points' in a hexbar linkage should be a part of routine maintenance, and inspecting the cable should be done then, too. Also, besides making an engine drift out of tune, friction in the linkage can wear out a cable sooner.
All of this nonsense must be why they invented the Sync-Link. I'll probably get a Sync-Link the day after my cable breaks.
.