This thread is ultimate proof that all reef tank invasions are not a matter of biology but a matter of psychology for the aquarist. Growback is a matter of biology.
To entertain, to keep, to watch another day (name your justification) the waving tufts of algae covering a system when the option exists to reverse that condition, it's pictured here, is a selection made by the aquarist. They want to be invaded, until something internal convinces them to will the uninvaded condition into place.
I bet in future years or months authors will peer into this possibility. Seems crazy I'm aware heh but everyone who makes a choice to take a tank back, or prevent it from ever going, are demonstrating modes of -resolve- researching and applying the toughest chemistry and biology our hobby offers isn't required.
All actions and parameters designed to ward off invasion should be applied in the clean, uninvaded condition that an aquarist has actioned into place. De cloud and garden the aquarium until balances are attained such that you don't have to.