Once you have Chaos Thurst, Internal Release will actually be good to use right before it because the increased critical does affect your DoTs, so long as it is activated before you use Chaos Thrust/Phleg. I tend to use IR/B4B at the same time right before using Chaos, then use them when they come back up (and due to the way the rotation works, should mean that regardless of when they are used, they should be active in time for a Chaos Thrust/Phleg.) Note that Life Thrust's critical hit only affects the intial hit and not DoTs so still use it for Full Thrust.