Tamron 24-70mm f/2.8 Di VC USD Lens Retest

A new set of ISO 12233 resolution chart test results are now available in the Tamron 24-70mm f/2.8 Di VC USD Lens Review. These results are lens sample "2".
 
I was not satisfied that the right side of my Tamron 24-70 VC lens-captured images was softer than the left. Since the right side is displayed in the site's ISO 12233 chart tool, I decided that Tamron should be given the chance to make the lens perform as I expected (some of you also requested this). Unfortunately, the lens performed better before I sent it to Tamron for tuning.
 
Here is the before and after comparison.
 
The first Tamron 24-70 VC I purchased performed so poorly that Tamron asked to have the lens returned to them. The second (retail-purchased) lens, while good, still had an issue (likely decentering). Now, after an attempt to correct the issue, the second lens performs slightly worse than it initially performed.
 
What to do now? I'll probably send the lens back to Tamron for a second repair attempt. I wouldn't be happy using it and wouldn't want anyone else to buy it on the used market. I will likely re-test the lens after the second repair. This testing process is very time consuming and therefore, very costly. This experience makes it hard to recommend buying this potentially very good lens to anyone.