Wait. Yes, Most of your info is correct, but I'm sensing a flaw in the logic. A heavy med protocol IS designed to kill adults. In your own words, you say that you cannot kill the eggs.
OK. BUT there's a limited number of "susceptible" adults...that is, a "finite number"...say, between 1 and a million. Assuming your "heavy med" is effective: they will all be killed in short order. Once they are dead, a monthly dose of broad spectrum systemic should take care of all hatching eggs, since juveniles are WAY easier to kill than adults, and maturation time from hatch to adult is longer than a month.
A CONTINUOUS heavy med protocol, (with the same substance) is doing at least one of two things: It is conferring further resistance to any adults who have survived, or, if there are no surviving adults, it's mostly poisoning you.