I have a DualSchock 4 and I play with it in PPD but i can't do frequent pressing with gamepad. I can't play on the keyboard, because it isn't comfortable. I have for you have one request. You can add this feature to modes "AC" and "FT": By clicking on the arrow (Right, Down, Left, Up) in these modes during the game it counts as pressing a button Similar Button (Circle, Cross, Square, Triangle) without delay.
If you want macros, there are programs that assign key presses to buttons on controllers, and I recommend Joy-To-Key. It doesn't help with spam though as even if you set the arrow keys to keys on your keyboard it counts the controller Circle, for example, and the keyboard key press as the same button, meaning it doesn't allow spam.