In the 2018 playoffs he had 7 appearances, 10 IP, 16 K, 1 BB, 0 ER.
That's the bar he set for himself. Whether or not it is fair to expect any relief pitcher to be lights out in those moments, I don't know. Not all relief pitchers have won reliever of the year 3 times...
If the Brewers are ever going to end their pennant drought, they need someone who is going to be unhittable in those moments or they need to go with a committee approach.