Vdimm doesn't matter so much as QPI/Vtt when it comes to this, are you sure you tried enough QPI/Vtt? Try lower as well, with ram voltage at 1.66, try 1.2-1.45+ (Depending on ram timings/speeds/uncore)

It very well could also be the memory kit itself, I have seen plenty of people RMA and get the same exact kits that work perfectly when they got the new memory back from RMA.

I have also seen PLENTY of people say they do not have bent pins, and be 100% sure of this, yet when I finally got them to post images I would find 2-10+.

So you may want to take some images of your socket as well and let someone have a look just to be sure this isn't part of your issues.