Sorry to revive a pretty old thread but I recently came up against this on my F32 with newly installed B16's.
It took around a month or so for the noise to first appear, what I did find though was after jacking the car up the noise would always settle, it made me believe that it was definitely a noise after preload from more stress on oem hardware.
I'm about to order one of the friction plates to try out, however I thought it was worth sharing that I also diagnosed that some of the sound was coming from the pinch bolt. After a little research it seems Tommy L Garage also thinks this
I posted about it in a UK facebook group and a member/mechanic replied back that the pinch bolt is 100% worth replacing, along with a good clean around the joint between the shock and the hub. From his experience he has found the friction plates do nothing and 90% of the time the collar needs a good clean and a new pinch bolt.