The safety concerns about a particular #Fosstodon moderator seem no longer urgent, since the account no longer has valid access permissions.
The Fosstodon admins (@mike and @kev) tend to take a few days to consider issues like this. They usually avoid saying things in public while they're thinking, so going silent is an encouraging sign.
As such, I think it's worth waiting for their response before you #FediBlock (unless this is just the proverbial straw).