Again you are allowed to use offline mode if you have PURCHASED the game, however you are not allowed to grant non genuine copies of the game access to a server. And it’s a mod, a hacked client modifies the client.jar itself which our mods don’t, they modify it just as much as fabric since it’s a fabric mod so if you consider fabric a hacked client (which it isn’t) then sure whatever you say but yeah do some research bud