Hey there!
You could try using “Get Input Key Time Down” node to count how long the jump button has been pressed. Then, create a variable like “jump key time” to store that value. So, when you call the “Launch Character” node put a Branch node in front of it to check if “jump key time” is <= “max time” and if false, it will stop calling the “Launch Character” node.
Maybe a node does exist, but I’m not aware of it, haha.