While I agree that CU, along with other AST abilities, could be a lot better and less lackluster, not even using it at all no matter what is just bad. I know there aren't that many fights where you can safely channel it, but for example if my party uses the "everyone stack in the middle and soak the damage"-method in A3 during the hand phase, I can use it after the knockback and just let the regen do its thing while at the same time recovering some MP. Even if you deem a class bad, it's not going to get any better by not using the abilities given to you.