SBE3 Point Of Impact Repair - Possible Safety Issue

I purchased this gun new late summer, and after a few dove hunts, I realized the POI (Point Of Impact) was off. I patterned the gun and it was shooting high (80/20) and to the 2" left with the 65mm shims installed, and while sighting straight down the rib, shooting 4 shots at 21 yards with modified choke. I contacted Benelli and they sent me a new set of shims that did not cure the problem. I sent the gun to Benelli and they adjusted the barrel stop ring, which is threaded on the magazine tube,

My new SBE 3 is having the obvious same issues as previously discussed in this thread. So, I called Rob Roberts shop and spoke with a guy there and he recommended not only trying different shims, but to slightly loosed the cap on top of the magazine tube by 2 or 3 clicks. I gave this a try and it seemed to help some; I went from an 80/20 to roughly a 70/30. Just curious, has anyone else here tried this with better or worse results?