Everyone should be allowed to be given a Platform including Fascists. If you Defederate them they get looked in there Bubble and you reaffirm their believes, meaning that there aren’t any people anymore to challenge their Believes. Which is just going to make them more extreme.
Even then I believe that their voice should be heard. But If they begin a call for Violence or repeated offenses against the Instances rules I would defederat them.
As it looks their on their way to do that tho.
I would rather wait until they actually do smth violating the rules, then act prematurely.