I've read about "EGR" ALS on this very site and to my understanding they just use an EGR valve to pump air directly into the exhaust manifold from the compressor housing of the turbo?
Nearly Correct it takes air from the inlet manifold side into an accumulator and when off throttle solenoids allow the air to be released through the egr valve and into two sides of e manifold, the fresh air reacts with heat and fuel and causes even more aggresive ALS
That's my understanding of it!