"Removing it removes the nutrients that it absorbed for growth. Killing it just recycles those nutrients back into the pond for growing the next plant episode."
P.S. When Bill says to "remove the nutrients", you need to move the FA out of the entire watershed basin above the pond. If it just decays on land, then the next rain will wash most of the nutrients back into the pond.
Sorry to make MORE work for you, but I want your work to be productive!