That's true, XInput is required. Instead of using my DS4 natively, I used DS4Windows to emulate a 360 controller. That allowed me to continue the game.
RPCS3 v0.0.5-7576-76f94940 Alpha
6700K @ Stock
16GB DDR4-3000Mhz
Zotac GTX 1080 Mini [+200/+200]
399.24 Drivers
Windows 10 1709
Vulkan
Only changed the render to Vulkan.
Game is playable to an extent. 30 FPS constant. Graphics look fine but special abilities such as homers burp or roll cause screen flashing when there is an explosion. No explosion = no flashing.
Warning: Video contains a massive amount of flashing. Epileptic warning.