@FediTips
I feel obligated to clarify, given that you have misrepresented my words in your reply.
I did not, at any point, talk about individuals blocking fascists. I talked about instances banning the individual fascists, rather than cutting off entire instances, as a choice of moderation style. I also agree that defederation is a valid option for instances, perhaps due to moderation burden, or because the remote instance in question is irredeemable.
An instance banning Vance means, on that instance, no user is capable of being radicalised by Vance's account. This is the same as if an open-signup instance banned Vance's account upon registration. This is the same result as defederating the entire remote instance for the sole reason that Vance is on there, except that otherwise innocent users on the remote instance are not caught in the crossfire.
Many of those remote users will not be aware of Vance's presence on their instance (especially when that instance is Bluesky), and therefore cannot be considered Nazis by mere affiliation: they have not interacted with him. Those users remain on that instance, and defederating will do nothing to protect them if he attempts to radicalise them; however, a moderation team can monitor the users of that instance and continually assess the risks and whether defederating later is reasonable to them. What can, in fact, sometimes happen is the opposite: the Nazi gets bullied out of there, or -- as in the Nazi bar analogy -- the users notice the Nazi and leave of their own accord (at which point I'm sure the calculus will shift in favour of defederation); perhaps such users move to fedi in this scenario, having not been ostracised for reasons they would not otherwise have understood.
Finally:
Does your instance currently block mastodon.social? If not, as some instances have out of concerns for its moderation & size, then that is an example of what I was describing which you quoted and responded "No." to.