Totally agree with JVB's comments on this one.
I have done the sync several times now with the use of my Gs911 to park the steppers and without, and cannot see any difference at all.
Always balance at around 3000-3500 rpm which seems to work well.
Only have to make minor adjustments each time to balance the throttle bodies back into sync with each other.
When at idle they are not matched but does not effect any noticeable difference in performance.
As JVB says, it's best to do the sync after a valve adjustment.