The Tier V Dyson unlock ability, Defiance, is receiving the cooldown reductions from the Tactical captain ability Tactical Initiative. Due to this, it is possible to use the ability much more frequently than intended. Per a post from borticuscryptic, all Tier V abilities are supposed to be immune to cooldown reduction.
Originally Posted by borticuscryptic
Others have noted in this thread, the fear of using Tactical Initiative (or other Cooldown reductions) to continually spam these T5 abilities... Well, I hope I can put some of those fears to rest when I say that we are making all T5 Reputation abilities immune to cooldown reductions. They will also share a region-specific category cooldown (currently set to 5min), although the only ones coming with S7 will not share a Region so this won't be noticed (Region = Ground or Space).