So Luffy managed to beat Doffy by going all out without having to gain a power up during fight. I think Doffy at best is a YC3 level fighter. A power up is needed when the opponent you are fighting is stronger than you even at your strongest state, which is why it was necessary for Luffy to gain a power-up against Katakuri. Now let's say Zoro beats Jack when going all out, without powering up during the fight. So he'd show his limits in that fight and then what's next? What if he has to fight King and then Kaido in the end? At what point would he NEED to get a power up? I don't know if you're implying Zoro might not have a power up during this arc at all, but if he's fighting Kaido he absolutely needs one, don't you agree?