Honestly, I don't think Keefe will deploy the 4th line in critical situations during the playoffs, ie. defensive zone faceoff protecting a lead in the 3rd period. That said, I do expect him to maintain his stubbornness in using them immediately after a goal for. It will never make sense to me how predictable and ineffective that tactic is. I honestly don't even blame the 4th line for that. What do you expect from them having to play the full sheet against the opposing teams top unit?
All that said, Reavo has been great since his return, and I am happy to see I am not alone in that assessment. He's a guy who can drag us into the fight if we don't have it on any given night. You can see the difference in physical confidence in guys like Domi, Bert, Gio, Benny, McMann, Caber...etc. Not suggesting Reavo is entirely responsible for that increased swagger and willingness but I do think the presence of a true alpha on the bench makes guys play a lot taller. Those guys aren't afraid of answering the bell on light/middleweights knowing that they won't eventually be chased up and down the ice by their heavy's.
The other team can chirp Reavo all they want about his playing time, or lack thereof. But at the end of the day a guy like that can moderate the game even without stepping foot on the ice.
You look at Schenner in game 3 against the bolts last year as a perfect example of how to police the game without ever needing to physically step in. Reilly and Point get tangled up and point goes flying into the boards. A brawl then takes place. In the immediate aftermath, Schenn just posts up in between the 2 benches and shuts up that lightning bench. Nothing came of that situation the remainder of the game or the series. The boys still played physically, and they never backed down from the fight.
That is what I expect Reavo will bring in the playoffs