Why? You can still readiness reset it and not use it until the 30 seconds is done.
I've found AMoC is significantly more damage than every other option if you can let it go the full 30 seconds and use it on CD. The problem is there aren't many fights where those variables will always be relevant. Use it on stone guard and petrification changes, feng it is very useful for, garagal it could be useful depending on how you handle the spirit realm, spirit kings you could get stuck having to delay so it as to ensure a full 30 seconds, Elegon is bad not only because it's zero bonus damage on sparks but I imagine it wouldn't scale with the buff like blink strike or lynx rush (not tested), and emp is a ton of target switching. Using it on Feng would probably be a dps gain but for every other encounter it seems there are more ways for it to be bad than good.