Idk, CoC = significant black lightning streaks.
If Oda bothers to draw ACoC, he usually makes it pretty clear with large streaks and SFX. Even in the panel you posted of 1035, Zoro's lightning streaks pretty much cover the length of all 3 swords,
and it has the 'zap' SFX in Viz.
In Zoro vs Lucci, the lightning is tiny and silent on one sword. It
could be ACoC and therefore KOH, but Zoro also looks like he's barely exerting himself whereas the last time he used KOH he kept complaining about how the sword will kill him if he keeps it up.
So there's two options here:
A) Zoro's using KOH but his stamina/control has improved massively since Wano to where it's no longer as draining for him.
B) the lightning on Zoro's sword is actually CoA, like Katakuri, Luffy, Coby etc... used:
It could be either tbh, it's annoying that Oda doesn't make these things clear and leaves us to make up for his inconsistencies.
Hopefully the next time we see Zoro vs Lucci we get more of an indication, for now I'll take it at face value and say Zoro's using high amounts of CoA with trace amounts of CoC. I don't feel like he's trying particularly hard atm, especially since he has no bandana on nor any indication of exertion.