It's hard, long and full of community maps :D

Come and play on 37.59.90.83:7707

or alternatively, set your search filters in game to Hard difficulty and tick perks enabled, the server name is "[KFNL] Long | Hard | Custom Maps | Whitelisted | Fast Redirect" in a distinctive orange font. Leave it to search for a minute or so as it may not appear immediately depending on where you are in the world.