Quote Originally Posted by Vejj View Post
Want to know if you really hold up all 3 dots on the boss )
TP exhaustion tends to happen when the fight plods along due to dead DPS or other issues. Invigorate is enough to keep you going for most fights; an all-out attack on a training dummy is a different story.

There are situations in endgame that will leave you unable to attack anything, so your TP will recuperate in this downtime. All the more reason to use DoTs: you'll continue to deal damage to the boss while you are running for cover or chasing down adds.