>Toggle the WDT input too slowly, too fast, or not at all, and a timeout will occur.

Reminds me of an article I read a few years ago about designing systems to detect when (human) train drivers fall asleep at the wheel. Apparently it was an arms race for a long time: Designers kept coming up with increasingly complicated tasks for drivers to complete to signal their conscious state, like tapping buttons with their hands or feet at various time intervals, while drivers, for their part, kept figuring out ways to perform those tasks while actually functionally unconscious...