[gumby79]

Is gravity not the most consistent power input known to man?
It takes out many of the variables that impact the engines power output at a consistent throttle position( yes these are variables /inconsistency that are relatively small ,so are some of the changes that are being chased).

Sounds like the OP did throttle stop testing.
setting there stop at 0 % throttle position. , in Neutral (this negates weather the computer is programmed to lock the torque converter clutch or have it in free spool for slower speed testing. Eg. GMC/Chevy Allison program running the TCC open till 5th[1st overdrive 0.71:1 ])

Gravity Drop Testing aka a more consistent version of Throttle Stop Testing was what I used to determine the air dam prototype that I built had a negative impact on my aero. I noted a reduction in speed on my 6% grade that is 3 miles long, this test was confirmed when Arrowhead ran my truck at Darko. Ditto for the bug deflector big negative (negated the 24% Improvement of my 3D boat tail canopy)

I thought his answer was pretty clear on additional testing is no.
For 2 reasons
1 Julian hook wasn't published yet nor was he participating in sharing his knowledge on this website yet . As well as Julian gets mad at me when I try and talk to him about pickup trucks as his book and I quote was specifically written for cars nowhere in the title does it say anything about trucks leave me alone." (Bitter taste words off most predators)

2 the concept proved unusable/ too troublesome in real life therefore was abandon.

The white paper is a good starting point for Research into where someone elce thought to look to correct the deficiencies of the produced 3 box pickup done to SAE standard, and of course lots of testing on these and more variables to find your best use case scenario of Form and Function.