I'll go with William of Occam on this one - to paraphrase - the least complex reason is usually the correct one.i appreciate the update.
so you are certain the damper backed out as a result of the 10k rev?
Yes, yes and the build was more than meticulous. So do I but picking up 2nd instead of 4th out of 3rd at >7500 and WOT is a whole different thing.Was this crank checked for straightness prior to install? Also, was the rotating assembly balanced? I'm banking on neither was done on a "meticulous" build. Only 3k miles means something wasn't right at all. I'm thinking you've been looking at the effects thinking they were the causes. Sorry to hear about the hurt motor but I doubt the damper had anything to do with the failure.
I spin mine to 8k all the time with fluidamper and without. Never lost a crank bolt and never loctite it. You're in good hands with Larry now.