Even optional, I cannot support the idea since it would likely mean the devs don't bother consolidating less used skills and semi-incentivize this aspect. It may seem silly to some, but reducing the combos down to mashing one button repeatedly makes the game itself feel boring. It's one of many issues I have with Dark Knight; you just spam Dark Arts half the time. Now if future expansions add a new lay of complexity to the combat system, thus making up for the lack of combo specific buttons, I could warm to the idea. Alas, Stormblood showed they would rather simplify everything. So I'm not too faithful it wouldn't just dissolve into 1-1-1.