That's a cool tool! But with the good style installer, you don't need anything else, because you hold the crank still with the tool itself and a wrench. But I like your idea, because most of the big box stores don't have the really good installer.
Agreement, that's actually cool.. . I always used vice grips on the fan belt pulley , or the "two longer bolts , and a breaker bar against a frame rail theory " . Llke it.