Holley/Demon Carb stumble

Watched it again.........

What it seems like is, it’s like there are two stages of stall.
You floor it, the car drives off the line at something less than 4200, then the motor gets a little burst, and goes to what sounds like about 4200.

But, what you want is to have the motor instantly jump to the 4200..... right at the hit.
It doesn’t sound like that’s happening on the video.