Thought Alex @ Stratified said they're doing the crackle tune w/o excess fuel?
I don't keep up with Alex and his tunes, so I don't know for sure. However with that being said, as a mechanic idk of a different way to add pops and crackles to your exhaust sounds, unless it's through your speakers. When at a race track or watching racing videos the crackles and pops you hear are from running too rich which usually comes from a turbo'd car with really large injectors. Running lean is a whole lot worse for your engine than running rich. Running lean too often can ruin your internals, running too rich usually only causes bad catalytic converters, o2 sensors and shortening oil life (time between changes).
Sorry for turning your sale post into tech talk.
*free bump