Yes, knowing in detail how something adds up to normality, allows you to predict weird situations, or design experiments that go outside the normal. For example, understanding the “weirdness” of quantum physics on one hand doesn’t change the everyday life; on the other hand it gives us quantum computers. Because we understand both how it is normal, and how to make it not-normal.
With Tegmark multiverse, we cannot even do experiments. At best, if we actually understood it deeply, we might be able to make better predictions about the laws of our universe. Maybe.