I have a XP-Pen Deco MW, and my pen gets items on the tool bar just fine (click the side button); although I do also use a standard mouse (better). Also, with XP-Pen, in order to reach the top of the screen, you must set up how much screen to access.
I’m loving Animation Paper more and more, the more I use it. It’s the closest I’ve come animating on paper the traditional way; and not getting in the way of the artist.