The best path I’ve found is to use Game Input Mode and Game/UI Input Mode along with the “Any Key” event on PlayerController. Note that “Any Key” receives all button press events, whether it be keyboard, mouse, or game controller. Make sure to untick “Consume Input” (click on the “Any Key” event and find the option in the settings for the node). Then just use “Is Gamepad Key” on the Key that comes in on the “Any Key” event to determine if the user has pressed a button on the game pad, or something else.
Best of luck