You can just press forward twice before pressing 4. For example to execute NDC you have to input bf4, b+BLK. But the trouble you are having is when you press f4 after the dash cancel, the game is inputing bf4 because you have to press back when you cancel (back+BLK). So after the dash cancel if you press forward, but than press forward again it will elminate that bf4 and you will get your f4 out instead. Sorry if that doesn't help I'm not the best explainer in the world lol