Anyone notice a difference shooting th Mark II with and without the thread protector?

I started to try to track any difference with and without but kept forgetting to do it. I noticed one time that the groups were opening up and I was wondering why. As I packed up, I noticed the thread protector, although rotated home, was very easy to turn compared to when I had started. Seems something like that would affect barrel vibrations.

I can answer that question now that I have tried with and without for more rounds than when first posted:
No difference.

Haven't noticed any difference with ours either. What I have noticed though is that it has seemed to shoot better now that there are a few hundred rounds down the tube.