Um i dont think so but i could be wrong...backside zone is usually scooping not down blocking
Perhaps "backside zone" is the wrong term, at least in the traditional sense. When speaking of traditional zone, you're right, SAB is a different animal and the backside would probably scoop. I was speaking to the idea that SAB is having the kids block an area and not a person, which IMHO, is zone at least in principle.
Coach Harris speaks about his failure to make a traditional zone scheme work at the youth level after three years of trying; hell, he even said that he had a hard time making it work at the high school level. This is when he started to use what he calls a "youth zone", which is very similar to SAB.
From what I know of SAB, it's teaching the player to run his track at a 30 degree track no matter where the defense is lined up, and making sure to cover the gap with your first step but to run that track. The youth zone I was talking has the player take a slide step to cover the backside gap, and if nobody is there, the player would move to the second level backers on a track (I was teaching a 45 degree track).
I like this zone scheme because it works with the trap series, the jet series, option, and passing as well (when used as slide protection). In this regard, it's all the same but with tweaks. This I like.