LOL, just reading, looks tough luck.
Though even thrashing an engine from cold in an engine only 8K old I would not expect that sort of damage in a new engine as its well within manufacturer warranty period and knowing first hand the extremes engine go through for long term durability testing thrashing from cold is a walk in the park.
It could be a contributory factor but maybe when you had a few issues with setting up the MS when running lean maybe some det happened. it can happen very very quickly, and with timing possible being out could have put the pistons under undue stress.
Talk of crank not being any good over 120bhp, can't see why that would be case, who has actually tested it

ours runs 115ish bhp so by that reckoning we are on cusp of breaking it, margins seem far too small to me. I'd like to see pictures of failed crank from a test bed with the dyno print out showing rpm/bhp/torque when it let go.
I am sure I looked up compression ratios of T-jet engines 120/130bhp model 9.5:1, 150/180bhp models 8.5:1, where as the N/A is 10.5 or 11:1 IIRC.
PS diesels typically run something like 16/17:1
Aaron.