Thanks for integrating the double-tap gesture on the Apple Pencil to bring up the new iPad context menu, it's a welcome addition and feels super natural.
There is a bug in the implementation though. When the menu is invoked using the pencil double-tap gesture, doing the gesture again while the menu is open will invoke another instance of the context menu, and stack multiple menu instances for every successive double tap gesture.
I believe the expected function is that a second double tap gesture would dismiss the menu.
This is present in 2.1.0.1703.