UE4 has a strong bias about the way things should work. If I am making something which is fairly well aligned to that bias, then it's fairly easy to make it work. But if I want to achieve something which is quite far from what the engine expects, then I have to invest significant effort undoing or circumventing what UE4 already does before adding my own functionality on top. I would greatly prefer to start from a blank slate, and only add precisely the behavior I actually want.

So basically this experience with the double jump just gave me a window into the level of complexity I would have to work around in terms of realizing my own goals.