And here we go with "you don't understand Sanji" argument over again.
Listen, I understand that people view characters in different ways, I really do. But there are certain things in a character that aren't up to me, you or even fucking Oda. The core of the character should never be changed, never.
It didn't change.
Sanji most hardcore values come from Zeff's teachings.
His hatred towards the Vinsmokes is not stronger than his desire to protect his friends. In WCI he learned his shortcomings. He couldn't have rescued Luffy without his siblings help. Since Sanji is not the MC that gets some magical instant power up in 2 seconds, he needed something that could make him catchup fast.
Hence the power ranger.
His hatred towards Judge is NOT on the same level as his "not kicking women", or "protecting" his friends desires.
Using the Suit is something he was reluctant at first, but quickly changed his mind. Oda even makes sure the character states the reasons for his decision.
"we are up against em emperor. I need power to protect my friends" etc etc.
It REALLY doesn't get any clearer than this.
You may not like the suit anyway, but saying that it "kills the character" or it "changes its core" is objectively wrong.
Besides, Luffy and Zoro are not Sanji.
They are different characters, with different beliefs, and different approaches to conflicts.