Any change to your pitch while fanning will break the swing chain.
Any change to your yaw (as you suggest) will decrease the
amount of damage you can deal (if you are not using dynamic
crosshair) as the target falls outside of the recticle. Maintaining
your view pitch around a 45 or 65 degree angle will increase
your chances of chaining 5 swings with medium stance. This
tactic gained momentum after only a few days following JK2's
pre-order release, and is not any cheaper than using the same
left to right strong stance 3-swing chain over and over, and over
(and over) again, which can break through any and all defenses;
however, it is just as boring. Also, it isnt as effective in JKA as it
was in JK2, mostly in part due to ghoul2's "sometimes its there,
sometimes it isnt" collision detection.