Kaido and Big Mom havent shown CoA flow barriers and ID and yet they can flow their CoC.
If Luffy's talent was really CoC, he would have used CoC coating long before FS and ID. But he didnt.
All that supposed talent to use aCoC in the same day talent-less Zoro used it too...
Ship theatrics are just CoC barrier that we saw in the clash of Luffy and Katakuri, they destroyed the environment too...
Paralyzing people is not going to be the case, imo. Nobody gets an easy advantage like that.
Even if it becomes a thing, everyone will have a counter for it.
They don't have to show it. We know they can do it, because they can coat their attacks in CoC. That's literally what we are told is happening. You take CoC, and coat your attacks, just like you do with flowing haki and CoA. There is no next level CoC required, in order to be able to coat your attacks with them. Next level CoC is destroying environments, and paralyzing people.
And no, Luffy wouldn't have been able to use it long before FS and ID, because Luffy didn't know how how to flow his Haki, prior to that. Flowing Haki is a requirement. Took Luffy 2 seconds to be able to coat his attack in CoC once he realized it could be done. Took him two weeks to learn Internal Destruction.
2 weeks for CoA compared to 2 seconds for CoC. CoC is by far and above Luffy's Haki specialty.