I have always thought that the length of the unsupported tube between the flex joint and the silencer was too great. In effect it makes the flex joint nearly useless because any vibration and engine movement has a long lever arm to work on the welded joint with the silencer.
I firmly believe that the new silencer mounting system if coupled with a second flex joint just ahead of the mounting would go a long way towards resolving the problem. Certainly if I had a pair of silencers that needed repair I would insert a flex joint.