He will go into the King fight with already improved AP and haki due to Enma, plus he's guaranteed to have a power-up during the King fight which will allow him to defeat him, so no, you're looking at Zoro after at least 2 power-ups who defeats King
AP matter little if the others stats are not high enough to land a hit or evade the enemy(same as Luffy ...AP was not enough).
So his stats are already high to compete against King but not the AP(cuz Enma once mastered gives such no other thing)unless you say he will learn a speed or something tecnique :unsure:.
And that'll be ? Learning to cut fire?
That barely can be considered a PU ,is not for broad use(as FS) at all it is more occasional than anything.