To answer a few questions...
The exhaust was the stock Vetterman setup, with hangars aft of this ball joint. NeverSeize was applied to all slip joints and ball joints at installation...in addition, all the ball joints were "exercised" on the bench prior to installation to insure they moved and that there was an even coverage of NeverSeize.
In conversation with Vetterman's, they indicated that the ball joints were to facilitate installation...that from a practical standpoint, they should be considered "solid joints" after a period of use because the NeverSeize wouldn't hang around at those temps. They recommended putting "Mouse Milk" on the slip and ball joints every time the cowl is off. Any play or movement in the system is supposed to be taken up by the exhaust hangar system (the stainless steel tube/fuel hose setup).
The other recommendation by Vetterman's was to install the hangar as far aft as possible (as close to the firewall as possible). My setup (remember, this is an -A model) had the center of the brackets positioned 6" forward of the firewall. When this is all reinstalled, I'll try to move the hangars further aft down the pipe. This will entail installing longer bolts (3" or so?) in the hangar setup to clear the nose gear tube on the engine mount.