Kaidou wants to be PK so it's Luffy's entire business to surpass Kaidou. The only possibility i find about ZKK is if Luffy had destroyed Kaidou's entire haki permanently using impossible powers, and Kaidou admitting defeat solemnly as he is no longer WSC after his haki's being perma destroyed. Kneeling in solitude and calm, he calls for Luffy to execute him. Luffy denies. Zoro accomplishes ZKK.
The better outcome in my opinion though, is that Kaidou to die during the last moment of his battle against Luffy, everyone watching the impossible and beautiful moment, a few pages without any dialogue but just Luffy and Kaidou battling away to their hearts' content, blood and explosion and wrath and poetry of artsy silent battle depictions, until Kaidou's body gives out and he dies standing or kneeling in front of new WSC: Luffy the MVP of PK Contender.