I think Oda is going in a path with Sanji that despite having DNA modifications, he will be able to boost it on his own by simply being different from his siblings, who are all fated to obey Judge despite anything else, emotions/willpower are also a one of the biggest must haves if someone wants to evolve and reach a Top Tier Level in the OP world.
Judge sees these emotions as weaknesses, but it is actually one of Sanji's strongest attributes, so Judge could be proven extremely wrong about that (like he did during WCI, and didn't wanted to admit)
Similar to how Diable Jambe got enhanced by Sanji himself as the time goes, it could be for his other powers, giving even more relevance to Sora's sacrifice, made in order to preserve the human emotions of her children.
Sanji using his hands to fight could also be interesting, because despite anything he is a skilled martial artist, more than his siblings ever showed to be, but by his own training and efforts.
Looks like Sanji already established from long ago that he wont use his hands to fight, but what if, in the path to get stronger without relying completely on his enhancements and being pissed about his unavoidable fate, he starts using his hand to fight and increase his overall potential? (Knowing he wont damage his hands anymore like before, even bringing a parallel about that scene were he got those handcuffs to explode his hands)
Imagine Sanji fighting Queen, then he says "
Fuck it, im turning you into food", then starting using his hands in a situation where they could be needed like his legs being busy at some specific moment.
(This is kinda unlikely to happen, since fighting with legs only is one of Sanji's most memorable characteristics, but its interesting to think about)