Testing on Annointed gear

Not sure if someone has already did the maths but I’m wondering what the duration of gear annointed with 100% weapon damage after action skill end is. Also curious about the interaction it has with Amara and her blue tree capstone. Using 2 action skills in a row. Does the cooldown for the annointed perk stack or does it reapply separately? Specifically with phasegrasp if you kill the grasped Target before the duration is over I’m assuming the buff activates because the action skill has ended meaning you get bonus damage, and can immediately follow up with another grasp, killing even faster because of the bonus damage. With a 7 second cool down you getting 100% damage more often than not. Just curious if that’s how it works.