I got my D-pad working with full 8-directional movement for a top-down game.
Axis 3 and Axis 4 in the up/down and left/right Axis Mappings should be set to a scale of 2 still.
The below portion is the .ini to import for RawInput
[/Script/RawInput.RawInputSettings]
DeviceConfigurations=(VendorID="0x054c",ProductID="0x09cc",AxisProperties=((Key=GenericUSBController_Axis1,bInverted=True,bGamepadStick=True),(Key=GenericUSBController_Axis2,bGamepadStick=True),(Key=GenericUSBController_Axis3,bInverted=True,bGamepadStick=True),(Key=GenericUSBController_Axis4,bGamepadStick=True),(Key=GenericUSBController_Axis5),(Key=GenericUSBController_Axis6),(Key=GenericUSBController_Axis7,bInverted=True),(Key=GenericUSBController_Axis8,bInverted=True)),ButtonProperties=((Key=GenericUSBController_Button1),(Key=GenericUSBController_Button2),(Key=GenericUSBController_Button3),(Key=GenericUSBController_Button4),(Key=GenericUSBController_Button5),(Key=GenericUSBController_Button6),(Key=GenericUSBController_Button7),(Key=GenericUSBController_Button8),(Key=GenericUSBController_Button9),(Key=GenericUSBController_Button10),(Key=GenericUSBController_Button11),(Key=GenericUSBController_Button12),(Key=GenericUSBController_Button13),(Key=GenericUSBController_Button14),(Key=GenericUSBController_Button15),(Key=GenericUSBController_Button16),(Key=GenericUSBController_Button17),(Key=GenericUSBController_Button18),(Key=GenericUSBController_Button19),(Key=GenericUSBController_Button20)))
bRegisterDefaultDevice=True