I feel more inclined to think its strain dependent. Of the 3 reversals I did with the Indiana Bubblegum, one was with Twenty20's kit, and the other two were with my kits and all 3 yielded the same results -full reversals but no beans. I've used Twenty20's kits multiple times before with great success on other strains. There was traces of pollen (almost none), and brown pistols....but no seeds were made on any of the 3 attempts with the IBG. I never had an issue getting viable pollen with my GG4 cut. Perhaps environment/temps/vpd/feed strength/humidity/ etc plays a bigger role than we are realizing? Just so many variables....
With the chemicals in any STS kit, its just atomized silver particles small enough for cellular absorbtion to block the Ethylene effects in the plant. Ethylene gas plays a role in stress/flowering/ripening and a handful of other things on top of sexual expression when flowering.
If I had pizza from 3 different places and got the shits with all three Id be more suspect of it being an issue with my guts and not the pizza. Much like humans, when it comes to plants they just react differently than one another and may have different outcomes by the same means. Ive reversed a ton of plants and still dont know why some stuff happens the way it does? Mother nature always keeps me wondering.