The difference here is that under requiescat, you have a set amount of GCDs limited by your MP. RoF has no such restrictions and so depending on your GCD you could either end it too early or not be able to get Tornado Kick off. A better solution would be to have it be more like Life of the Dragon and Nastrond/Stardiver, so you can only use it under RoF, but it doesn't end it. Obviously, either way it is just copying another job and not adding anyting unique, which might or might not be an issue for some people.