>>The problem with Titanic research is that too much is known, but too little is revealed. <<
Very true. A good example is the sub-bottom profiler data of the port side of the bow from Polaris Imaging. Apparently, that data was deliberately withheld from the public.
>>As far as the lower angle of the breakup is concerned, the angle can be calculated quite handily from data contained within the testimonies of survivors. <<
Not very precisely, especially when considering some of the conflicting accounts from witnesses at various vantage points. What we can say is that the ship was still intact at 10° when water was coming over the bridge. That can be quantified quite easily. At what angle beyond that did the break occur is less well defined from eyewitness accounts. After all, nobody was measuring it especially once the lights went out.
>>It showed the strains on Titanic's hull did not exceed the design parameters set by Harland & Wolff until the angle reached 11 to 15 degrees.<<
It is amazing that it took so long to figure that out. As in so many other cases, there usually is simpler way to bracket the results without going to great expense as I described in my article
Why a Low Angle Break? on this site.