Well I'm not clutching at anything. You initially highlighted a 2% range which showed a 0.5 improvement but that would of course be a fail on Dragy. You are correct in saying that in your case on a 0-100mph if you managed to find a full -1% gradient then you would at maximum find an extra 0.24secs. However, In my example the -1% only shows a 0.03 sec benefit. I have a test where I run a quicker 1/4m "uphill" than I did "downhill" though which skews the argument further.
On the vbox, you can launch it down a 15% gradient and take a pic of your display, you can plot it in performance tools and no one would be any the wiser, you can run with 1ft rollout on and cheat it even more.
Dragy is much stricter, you can't cheat it at all, there's no 1ft rollout full stop and if you launch it down a hill its an immediate fail. The only benefit you have on the Dragy is finding a road with a 0 to -1% gradient. With the live leaderboard you can see what everyone is doing whether that run is at 0% or -1% or 0+%. If I see 2 cars on the Dragy leaderboard with the same time, i'll then compare their gradients, if one is at -0.5% and the other is at 0.5% then the car at 0.5% obviously gets placed higher than the car that run with a -0.5%.
My runs downhill for a bit and then uphill which gives me an advantage? Are you serious? Even using the words downhill and uphill as you are doing with a -1% gradient is crazy, the road I use is as flat as pancake to the naked eye, there is no downhill or uphill sections. My 1/4m runs were +0.12% in one direction and -0.12% in the other direction. Are you seriously trying to tell me that +0.12% and -0.12% offers any advantage or disadvantage? The 11.58 1/4 should have been quicker then as I done that with a 0.12%+ gradient? That's just getting ridiculous, I couldn't give a monkeys if my time decreased to 11.57 to correct for the 0.12% uphill.
And the golden question, who is to say that the 3rd party applications such as DBN scanner and vbox verify are accurate? Neither are endorsed by racelogic, they are based on theoretics and not actual recorded times. Like I said, I have both units, the vbox still has its place but I much now rather prefer the Dragy, welcome to 2018 I suppose rather than 1998.
I guess the best thing to do is always run with a positive gradient in Dragy, I know the direction for the +0.12% "uphill" section on my private runway so any times I do on Dragy should be slower than the real corrected 0% figure. Perhaps Dragy will incorporate a correction function in the future for those that do manage to run between 0 and -1% but based on what I have seen as the -1% is so narrow in the first place, you are talking hundredths of a second, perhaps a tenth or even 2/10 at the higher full -1% range and that would be off a 0-100mph+ run, not a 60 which is done in such a short space.