Cool!
The qukeys are not one-shots, they have to be held.
I initially thought I’d need to hold page down, but find that it works just fine tapping. I’ll use cmd-downarrow to get to the bottom of a page or if i’m using something like ‘less’ the pager, there are other ways to handle quick nav. The fn + arrow/arrow combo keys can all be held if you want, just hold the palm function key and hold the arrows and or combo arrows as much as you’d like. I do use the fn + thumb shift with the arrows at times so I can hold the arrows. But I find myself not needing the other modifiers to be held with arrows.
Blank thumb key is space.
I say use whatever you find most comfortable.