Zoro already got all of his possible power ups for this arc and seemingly use it in his fight against Kaido.
He got Enma that enable him to use his armament effectively and used it to cut Kaido.
He got Kinemon sword style and used it to cut Kaido's fire and Prometheus.
He got CoC and used it to wound Kaido a wound that will stay with him.
Sanji got only one power up , namely his RS and used it only to rescue Momo. he will have to use for sure soon again but he will got some haki power ups.
most likely better CoO with combination with his RS (hiding his presence as well beside invisible or FS)
he will got other power ups as well , like CoC , better armament or some another form or transformation.
What are you talking about?
Zoro already had powerful CoA haki. The manga hinted at his ability to cut Kaido when he cut and killed the PH dragon. Enma right now is making it harder for him to properly control his haki. Right after enma took a huge amount of his haki he took it right back. That proves he could always control large amounts of haki.
We don't know when Zoro learned enma. He just display that power for the first time in Wano. Let's just give it to him for argument's sake.
We still don't know much about his CoC. Is asura CoC or does he use CoC everytime he uses asura?
So right now he hasn't had any growth. His growth from enma what come from mastering the sword and/or creating a black blade.
His growth from CoC will come from being to use it at will.