I'll say it only here without tagging anyone because I don't want to start some conflict or whatever and get banned for it.
But whenever I see "sanji can't have CoC because WCI", my brain hurts.
Sanji's willpower portrayal reminds me a LOT of Hal Jordan. Initially doesn't believe in himself much, creates excuses all the time, fails, gets down, then gets up, bounces back to action, and shows what he's capable of.
This "bouncing back" willpower theme is something SO COMMON in fiction (Aragorn in LotR movie trilogy as well, etc), that it makes me wonder if a lot of people in this forum read/watch anything else besides generic shounens and One Piece.
If Oda makes Sanji goes this route (which seems to be the case with immediately asking for Robin's help, and telling Chopper to "not lose hope in Luffy") and gives him CoC, also working with his identity theme of accepting his Vinsmoke heritage, without stopping being his own person, it can DEFINITELY be something REALLY special and I would LOVE IT.
Not something I would bet my chips on, though.