[jeffba]

There is what is called Polling of the sensors. What each manufacturer is I do not know. The correct answer is if a fast catastrophic failure of the tire (blowout) happens when the sensor is not being polled, there will not be an indication.

What you are looking for is for ones with the shortest polling time. That may wear down batteries sooner than some people would like.

I really doubt if you find one that is truly continuous