The only reason I don't find a problem with it is because the buff seems to just stay there. I'm guessing you're talking about the bonus damage?[/quote]
There's an annoying thing where each element inflicts a different status condition, and each elemental attack only does full damage if its hitting an enemy who is inflicted by a status condition caused by a different element. When mobbing enemies with high HP, you need to start slapping them with an element, wait for the status condition to trigger, then start hitting with the next element. A few more monsters will inevitably walk over and get hit by this element and affected with a different status condition, so you need to rotate to the next one to keep your damage output high.
Also, single target damage on anything requires charging all 5 elements, using blast, then charging all 5 elements again, then switching back to blast.