Mirage third ability T3 not reducing buildup despite it reducing cooldown

[T_UN4]

old T3 used to reduce buildup cooldown but the current one doesn't affect it, the T3 cooldown reduction only applies to using the ability manually which doesn't make sense

 

[tidowu321]

yeah im not sure how mirage is expected to get full value outta his abilities if it takes 15 seconds to build up max stacks