That blocking has always happened, this site used to block the word "waterwolves" as it was a sort of competitor forum for a while before it tanked. Not really sure why it blocks vendors though.
Not sure honestly. My knifefish are not particularly aggressive and don't use electro-navigation as other knives do. Apparently, the interference in signals can cause them to be aggressive (Anecdotal evidence) so honestly I don't know!
Seeing photos of this knife it looks to be on the "blind, electro-location" side so they may be more territorial than others. Honestly not sure.
African brown knifefish have been another fish I’ve enjoyed from afar for a while too.
What are your thoughts hendre if I were to do an experiment with them in a 55 with say 1 brown and 1 granite in the beginning and see how it goes? If anything goes wrong I have tanks for the injured knife to live in peace for the rest of their life.
Personally I would just get a group in their own tank, they are lovely to watch when they just glide around in formation. You can always try, but I have found mine to be more outgoing with a group.