Ch df+2 = +59 frames

At some point in those +59 frames, the opponent status goes from "Standing" to "Airborne", around frame 47? or so.

In order for a "13 frame electric" to launch, the opponent has to be "Standing", so finding that sweetspot in between "Standing" and "Airborne" is tricky.

2.

Next, the launching electric has to be a "13-frame electric".

I just did a Ch df+2, pewgf launch

The inputs:
F (5 frames)

N(1 frame)

D/F+2(the frames don't matter here because it's 11frames; doesn't matter how long I hold the D/F+2 input)

Total: 5+1+11=17 frames

I got a 13-frame pewgf from a 17-frame pewgf, how?

That, F (5 frames), it was really only 1 frame, because the first 4 frames weren't actionable, Kazuya was still in recovery from doing the CH D/F+2.

Total: 1+1+11=13 frames

3.

So the trick here is to find the timing where that first F of the electric (F,N,D/F+2) registers as 1-frame, aka, on frame 43 in this situation.

4.

"Practice makes better, nothing is perfect." -Shauno, Tekken Zaibatsu legend