If we look at Sanjis development we can see he became able to use Diable Jambe easily after Kamabakka. Diable can be inner damage version of advanced COC while Zoro uses his to make a barier. I also though why not touching thing doesnt happen in Sanjis case but it may be triggering with activating domain. AdvCoc makes people faint and if we look at Jyabura he faints after taking one hit to his head, same also happened to Luffy where he nearly fainted but got back up. If Diable burned people wouldn't Luffy burned but he didn't, this may be explained by Sanji having burning spirit. We see Dj as fire same reason we Ashura which is strong spirit can show illusions and zoans can see those which we see chopper reacting to Zoro. Sanji may also be a Lunarian but that is highly unlikely.