There were some questions posted as to trim drag of aircraft. It is common practice on the large commercial jets to move fuel both fore and aft to reduce trim drag. I believe for instance, the 747 has a rather large tank in the tail for just this purpose.

In terms of static stability and speed of the aircraft, these do change with aircraft speed. An airplane can be quite a bit more tail heavy at the upper end of it’s flight speed, the problem is slowing for landing. Airplanes such as a P-38 were able to use this, since their gears retracted rearward.

Today, with the electronic stability augmentation systems like on the F-16, the airplane can be flown in what would be considered unstable. Interesting to note, that the F-16 C increased the size of the tailplane by about 10% so that the bombing load could be increased in total weight. If memory serves me correctly, I believe that they were able to add two additional 500 lb. bombs with this change due to the tail carrying more of the load. In a sense, aircraft flown in this configuration are canards flying backwards.

On model pylon racers, most have difficulty just meeting weight with the required equipment, however, I have seen one that had instrumentation onboard to measure airspeed. It would not be too difficult to measure G loading. Perhaps more important would be taking data to determine what flight path gives the fastest times. A larger radius turn results in a lower loss of speed due to lower G loads, but results in a longer path. The trade-off here is how well does the airplane accelerate after the turn. Acceleration is influenced by the propeller selection.