The hot zone juggles are pretty easy. The scramble ones are more difficult and I've played around with them a bit but they seem inconsistent at times with the first falling block of concrete
It IS consistent, but I figured out that the last move you use to smack your opponent into the generator will determine the angle. If I use, say, P+K with Momiji, then the combo I did in the video won't work, but if I start it the exact same way, then it will.
Think it's best to come up with a Scramble combo that starts with a power blow into the generator, that way you don't have to remember what move you should use if you want to go for your usual combo.