Braking harshly to compress the suspension an inch, I wish. Rolling off the throttle will compress the CT suspension more that that
Anyway, I have never noticed any sort of noise and am not aware of any sort of anti-dive system. I would be looking for some bit of body work or cable that might be out of place. There is bugger all room at the fork clamps, maybe something is making contact when it shouldnt.
By the way, whilst the CT is a decent bike, please try a multi. I regret not getting another one and if you have put up with a chain on your XLs then happy days.