If I were you, since you have made a million passes....I would raise the LCA up, and make a pass.
If it doesn't work, I would go back to the middle position....and try 6C and 2-3R.
If those make no changes, then I would change the way I launched the car.
Ya, I'll try LCA hole next time. I lower and raise 2 step rpm and tire pressure depending on perceived track prep. Aside from that, I can't really change too much of how the car launches given the limitation of the stock computer. I have to dump the clutch--any clutch slippage and the computer will take over and close the throttle body.
I'll see how the upper LCA hole does and get some quality video to study.
Thanks Kelly