It does work, Tom, thanks!
Sorry for the late reply, since this is a project for me I just have to squeeze time between client work.
Since I specifically want to use it on the homepage, just adding an is_home() setting does it. However, if the page doesn’t have a header, that’s a great question! I’ll try to poke here and there to see if I can find a solution.
However, there’s an “issue”. If I set the Page Header content to be Fullscreen, the menu doesn’t appear until you scroll down.
I found out that if I change the height of .generate-content-header { height: 87vh !important; }it does look quite well. This, however, I am not sure where to change it so it doesn’t break other pages (and so I can update GP and such).