Just a comment i made recently
Sanji said this last chapter
Then
Sanji developed an even stronger CoA in the middle of the fight, but dont fool youself, thats actually just what Sanji thinks it is..
It's clear as day that he felt something else different with his CoA coating, he thinks he suddenly developed something new exclusively for the Exoskeleton in a span of 6 chapters, but thats not simply CoA
Editor's note chapter 1031
Then Oda draws Ifrit Leg with white CoC sparks so it wouldn't be that obvious for us, it would overshadow Zoro's CoC after 1033
What Oda did drawed:
What he actually wanted to draw:
Confirmed Ifrit Leg is Devil Leg + CoC, he is just developing it