The problem with this is that there is no way to know ahead of time what the pool difficulty is and how long it should take to find a share (unless a non-vardiff pool and you are doing the math). You could be resetting the device too soon, or waiting too long.
There is a
feature in the works for BFGMiner that does something similar, only it is based directly on the difficulty of the pool and works without additional arguments.
Neat approach, but maybe the issue doesn't really need that much over engineering - even at extreme pool difficulty, if the module/chip/serial (whichever is used to send jobs to the blade) doesn't produce anything in 120 or 180 seconds (or even extreme - 300 seconds), it can be safely assumed as dead, you kind of want it reset, right? Or am I misunderstanding the issue?