I don’t understand how one can advocate for censorship, yet be incapable of defining what speech should be restricted.
I feel like Sarah defined pretty thoroughly the type of speech that should be restricted when she said "If you are advocating for the literal eradication of people because they are part of your “out group”, then into the bin with you.".
That feels like a line that we should all be able to agree upon, and yet there are still many who bafflingly say that we should respect Nazi's ability to spout Nazi propaganda and recruit online.
You're 100% right that the exact threshold at which speech verges from the "unpleasant but tolerable" to the "dangerous and requiring censorship" is fuzzy and subjective. But I think it's entirely safe to say that when what you're discussing is the eradication of groups or even "just" individuals, you're on the wrong side of that threshold, plain and simple.
We can talk about where exactly that line falls relative to other issues, but that's always going to vary from person to person in the fine details, but anyone who thinks that literal Nazis should have a safe space to discuss actual Nazi propaganda frankly isn't someone whose opinion I'm going to take seriously, in the same way I wouldn't take seriously someone who argues the Earth is flat (though - being harmless - I'd certainly support their ability to talk about Flat Earth online without censorship).