My opinion matches Yahtzee (Zero Punctuation) on this--if I've performed the arcane series of actions you intend me to do in order to defeat the boss, then I should only need to repeat that 2 or 3 times to prove I know what I'm doing (because the first time might have been a fluke). I shouldn't have to keep doing it for minutes on end in order to whittle the boss's enormous health bar down, that's just making things tedious.