Very neat idea, because it opens up so many more possibilities for what you can do with the stick clicks, which are very useful (if somewhat easy to 'misclick' while moving or adjusting the camera XD). The one concern that I think this MIGHT cause, is how it might inerfere with the Duty Actions - which are currently assigned to R3 when you have an active hotbar selector pressed, either L2 or R2 for a standard PS4 controller.

So these would probably have to be restricted to use while no cross hotbar is active, I suppose?