You can use CoC in an attack without infusing it properly to destroy your opponent, that is the distinction between base and adv CoC. Luffy has been using moments of base CoC in his attacks since punching Blackbeard in the pre skip.
Yamato likely doesn't have adv CoC either.
Kaido was calling him a dead man walking because he was going to kill him before he'd have the chance to unlock it years and years down the road, not that he was too nerfed to unlock it.
Kaido was directly saying Luffy was not "one of the strongest" with that statement, that is the key point.
But according to you "one of the strongest" Zoro should "be happy" with a small scar in Kaido's mind. I don't know how many gymnastic flips you have to pull off in your head to get to that conclusion.
Yamato says Luffy is the ONLY ONE who can challenge Kaido, she is not "one of the strongest", neither is Zoro, she puts Kaido and Luffy on that tier, no one else.
Yamato says Luffy is the ONLY ONE who can challenge Kaido, she is not "one of the strongest", neither is Zoro, she puts Kaido and Luffy on that tier, no one else.
The only one doing mental gymnastics here is you (to the point of claiming Roger and Oden didn't use that and Yamato, who was factually shown to use it, doesn't use that) to justify your Zoro downplay.