Ok, I know my ACC isn't amazing so I don't have much room to talk. But I think it would be better for OP to work on improving ACC on easier stuff than button mashing harder stuff to get PP. Imo if you get anything less than an S on an FC your not really playing the rythmn and simply got lucky that you didn't break combo as you managed to mash your way through a song. I'd focus on getting your account ACC at least to 95% before going after harder maps.