When you spam Triple Swing attacks, don't hold any directional key because that would be unnecessary either way. Those keys are only registered the moment they get pressed down, if held over a long period of time, they're just registered as not being there.
So, do whatever you usually do, jump left/right and attack if you want to, the moment you start spamming 3 (or more key strokes) to perform Triple Swing, let go of the directional keys, then when your brain tells you to "Final Charge", hit the direction and attack, voila. I must say it's not very useful beyond gathering mob for the sake of convenience when Smashing/Fenriring. Perhaps when you get Freeze Standing, it will be much more useful.
I personally would use it to maintain combo count mainly.
So, do whatever you usually do, jump left/right and attack if you want to, the moment you start spamming 3 (or more key strokes) to perform Triple Swing, let go of the directional keys, then when your brain tells you to "Final Charge", hit the direction and attack, voila. I must say it's not very useful beyond gathering mob for the sake of convenience when Smashing/Fenriring. Perhaps when you get Freeze Standing, it will be much more useful.
I personally would use it to maintain combo count mainly.