LOL, Tamko, I know them very well. They are based in Joplin Missouri. Tamko is trying to get OUT from under their warranty by getting YOU to apply and warranty a roof cleaning, in effect, taking them off the hook.
It is NOT true there is nothing you can do to prevent algae regrowth. I have done hundreds of field tests on AppleSauce, and roofs cleaned with this mixture stay clean longer. The AppleSauce formula is posted here.
Borax is a proven mold preventer, it is used in mattresses, and wood is treated with it to prevent mold.
Back in the old days of roof cleaning, when we were cleaning large chunks of subdivisions, I would take one side of a street, and clean every other roof with the Borax mixture (AppleSauce) and then every other home with just a Chlorine/TSP/Water mixture (No Borax)
I made notes, and came back every year, to check on my experiments.
The AppleSauce treated roofs held out anywhere from 6 months to a year longer before showing signs of Algae regrowth.
Even after 4 to 5 years, when both the AppleSauce and Non AppleSaUCE roofs were both dirty, the Algae was thicker, and far more visible.