I might wanna refute this one.
Zoro didn't use KoH.
But he did use AdCoC , and It's a good thing that he can use it willingly without any restrictions.
Hahava hunt spot after effects looks a lot like Kaidou thunder Bagua where Haki trails are visible. CoA shows trails during attack or clash.
AdCoC shows Trails after wards as well.
Haki Trails on Zoro and Law after being Attacked.