There's so much wrong information here.
Zoro mastered enma during Wano.
This scene has caused so much confusion because some don't understand what the manga was telling us about Oden use of enma or what Zoro needed to do to master enma.
During Zoro battle against King, Zoro realized Oden could use enma as light as a feather even when using so much (overwhelming) CoA haki. If he wanted to master enma he needed to do the same.
Where people are confused are they believe Oden is always using overwhelming CoA haki with enma which is incorrect. The scene tells us Oden can use overwhelming haki with enma, not he always use overwhelming haki with enma. Zoro mastered enma by showing enma he could also use overwhelming CoA haki with enma.
That explains why we don't see smoke or flames on enma every time Zoro uses enma. Oda created the concept smoke or flames on a swords represent overwhelming haki is being used when Zoro first used enma. That was before Oden's flashback. We never saw smoke or flames on enma when Oden used enma so that means Oden never used overwhelming haki during the flashback.
KoH was created from Zoro taking the requirement needed to master enma, using overwhelming CoA haki, combining it with ACoC, and turning it into a sword style.
Zoro never used KoH against Lucci. KoH has a very unique look. It's not tiny sparks that we can barely see that we need a close-up view of his swords to observe. It is large lightning that flows or wraps around his swords that is at least as long as his swords. It is drawn the same way every single time we see it.
These are perfect examples of KoH.
That's very different than the small lightning CoA he used during his battle against Lucci for one scene.
Besides, it's very foolish to believe Zoro used KoH against Lucci when Lucci couldn't even overpower 2 swords Zoro.
KoH 3 swords Zoro >>> CoA 2 swords Zoro.
That would be like Lucci handling G5 Luffy better than G2 Luffy.