Fishing for AM yes, but there are some scenarios where it could probably increase the ST damage as well, but that is only in the case of Nether tempest.
The only scenarios i can think of are Galakras in the situation where you have downed the drake and there are still adds up. In my situation we kite the assassins on Nazgrim encounter next to him so the can be cleaved down by the melles and everybody who is capable of it, Malkorok hc too if u can manage to multidot the adds before they be griped to him by the tanks and other melles(but that's pure padding
), and most brightest example will be Klaxxi, because most of the time ther eis another bug next to the kill target, so that basically increase your damage on the said target.
Im not sure but i actually use Fire bomb on Malkorok because the adds die fast and when they die that's 2 explosions right next to the boss. Same with the adds on the Dark shaman encounter. Our tank deal with blobs in a manner that leave them next to the boss and we aoe like mad and i stoped blinking in to spam cone of cold and AE and just dot as many blobs i can. I must say its fun because all the time i watch explosions around the boss, because the adds die so fast. Still blinking in with cone and AE is more effective ofcourse (what can i say sometimes i like watching things blowing up hihi)