Yes, but how do you determin the actual reason for a bounce? The test would need to have all the same starting conditions and then let some users have a better performing version or something like that. But at that point one would probably rollout the better performing version anyway. Maybe artificially worsen the performance and observe how the metrics change. And then it is questionable, whether the same amount by which performance decreased would have the same effect in reverse, if the performance increased by that amount. Maybe up to a certain point? In general probably not. In general it is difficult, because changing things to perform better is usually accompanied by visual and functionality changes as well.