I have replicated the grappling hooks from MineZ. You have a configuration. The lower the number, the more powerful the grapple is.
If you've ever played MineZ before, you know that horizontal grappling was disabled. In the config, you can enable it or disable as you please by adjusting the minimum height.
Here are my recommended settings.
Code (Text):Fail message: '&cYou cannot grapple horizontally.'
Minimum height: 3.0
Grapple speed: 5.7