It might be appropriate to explain how the engineering process works in industry. In the case of trim surfaces, the designers of each airplane looked at history and theory, and committed their trim design to paper. That design was reviewed by senior engineers and approved as part of the entire drawing package for the new aircraft. Sheet metal gets cut only after the calculations are reviewed and drawings are created. Once the entire airplane is documented and parts built and assembled, the flight test dept gets to demonstrate that the prototype aircraft has the behavior and performance that the engineers calculated it should have. Flight test is a design verification and quality control function. The designer has calculated and committed to paper parts that are expected to result in the prototype aircraft meeting performance expectations and certification standards. If the flight test demonstrates different behavior or performance, that means that the design engineer's calculations are off and there is some head scratching as to root cause of that "delta".

So the different numbers that you have identified likely reflect the different design calculations, not tuning by the flight test department.

I offer this perspective from 40 years in the engineering world.

I used to work with a gentleman who was the chief designer at Piper for 30 years. Jim has some interesting stories about the engineering process and flight test issues.

Hope this info is helpful,

Wes
N78PS