So far what we seem to be learning is that the two forward fin attachmnent bolts need to be 10-32 instead of 6-32. There is sound logic to building test vehicles like a tank and trimming the weight to boost performance and range after you have enough data to figure out where you've overbuilt. The X-1 was ridiculously over-strength (20 G's) so it could survive in an unknown flight regime. Until fairly recently, aeronautical engineers would take computer runs of aerodynamic simulations and then substitute the numbers with their gut instincts, knowing that the simulations were missed a lot of important details and often got the whole flow wrong. Younger engineers are probably too accepting of PC outputs even when the simulation is pushing into regimes where the codes haven't been sufficiently tested against wind tunnel and flight test results.
