I think at the lower levels this has some footing, but you might end up with a bunch of people with higher keys than they could conceivably time if they hit a good streak, but not the end of the world. It would absolutely kill push groups though as they generally will cycle the keys in the group and no one would want the entire groups keys go down if one of the pulls happens to botch the run and everyone runs out to reset with another key in the group.