Funny you mention this part.
I saw a comment on a youtube video talking about a archetype from literature called the "Shadow". The basic idea is that this "shadow" is things from a character inner self that he/she usually buries and rejects due to principles or whatever. The "creator" of the terminology stated that humans must always have a point in life when they need to confront elements of who they are, and either accept it by embracing it, or dealing with it in a more mature way.
The idea being applied to Sanji is that Sanji ALWAYS have hidden this particular part of his life. As he himself stated during WCI, the Vinsmokes represent everything that Sanji stands against. Royal fuckers with fucked up morals and ethics, that don't give a fuck about anyone but themselves, and view others as mere tools for their own gains. But whether he likes it or not, he's a Vinsmoke.
He should accept his name, and, only after that moment of acceptance, decide what he's gonna do about it. Is he gonna follow the footsteps of his family? Is he going to come to terms that, despite his family name, he's still free to do whatever he wants?
As I've said it before, this plot, despite understand why people don't like it, has A LOT of potential for very interesting and engaging conflicts for the character, which is EXACTLY what made Sanji so appealing to me since the beginning. Not JUST his fighting style and slick suit, but also his ordeals, his resolves, how he takes the hand of those that reach out to him, how he's grateful to those who are special to him, willing to sacrifice everything for them, etc.
Give me the "Venom-Sanji" mini character arc, give me "making true piece with himself" moment, give those juicy epic character moments.
That's the absolute good stuff to me.