Sadly, Nietzsche was palatable to the Nazis regardless of his sister. It’s been awhile since I read any Nietzsche myself (I went through a phase of reading his stuff in college), but IIRC his dislike of antisemetism was primarily because it’s seeing oneself as superior regardless of whether one is a wretch themself. He thought only people who crush their enemies underfoot (and are thus super special boys with noble aristocratic souls) could puff themselves up with such a superiority complex.