Without delay, I immediately enter the second portion of the throw
I'm having a completely different experience here.
Second part (8264H) needs to be inputted with a big delay, basically as soon as the Combo Throw message appears on screen.
You have to be fast and the game doesn't accept more than 2-3 wrong inputs.
So for instance these will be accepted:
1) 821476H
2) 872146H
The following will NOT be accepted: 89632147896H
You also need to be fast.
Now for the third part I can't seem to get it right but I think you need to input it as soon as the first one is over. You just have the same "no more than 2-3 dirty inputs" thing, and that's way trickier when it involves diagonal inputs.
I used to be able to input it in DOA4, altough with some issues, now I've failed for like >30m straight in the Command Training mode.
It's strange that the command buffer is so strict when for the other command throws it accepts a lot of dirty inputs, way more than Raijin does =/