It’s a conundrum but Knies is playing imo.

Well the good news is the Leafs can put out 13 competent forwards. In a long playoff run (hopefully), there will be an injury ,the 13th guy is bound to play.
Same with the Dmen,,,,,nine competent Dmen. Though the six that are on the ice on any game, don't always play competently.

Tough to see Knies as a scratch when he plays playoff style hockey. He offers something that a lot of Leafs don’t have to their game so barring an injury he stays.

I think the top 11 is locked in:
Bertuzzi - Matthews - Domi
McMann - Tavares - Marner
Knies - Holmberg - Nylander
(In any order)
Dewar - Kampf - open spot

I think the open spot depends on the opponent and the situation. If the draw Florida, Reaves likely plays more. If it’s Boston, Jarnkrok plays more. If it’s the Rangers, probably Reaves.
I could see a situation where Reaves is 100% the guy for game 1 to help set the tone and police the ice for the team and then depending on how the series progresses Jarnkrok could draw in as needed. It’s tough for Jarnkrok to just jump back into a game after a long time due to an injury and to have that game be the first of a playoff series. He will be needed for the PK but it’s best to see how things play out before rushing things