We have to approach this otherwise.
What do we know? Zoro showed exceptional talent with all types of haki. Regarding CoC we have seen him enter a fight with zero experience and master its advanced applications within basically a minute after discovering.
We know that the sky gets split when two halfway equivalent adv CoC users clash. Or as recently discovered, when you release a CoC bomb, however that one might works. Probably it's just releasing all your CoC reserves in a burst.
Adding 1 to 1, there's no other result than 2. Zoro is able to split the sky. He simply didn't find a foe to clash or release that much adv CoC against.
Wether he gets his chances with Pranks really depends on the reinforcement they're calling in. Of luffy is around, I really doubt that Oda would give Zoro such spotlight.
At best, he'll get his chance on Elbaf. If not, he'll split the universe against Mihawk.