Recast time doesnt stack?

I equipped a icy plate and a dancing deco. But it seems recast time only works for one at a time, whichever is highest. Is there any way to reduce recast time more than 25%?

 

as much as i know 50 % is cape for recast time

 

So it stacks but capped at 50%? Is it same for attack speed?

 

Attack speed is capped at 100%

 

100% attack seed increase = 2x faster attacks
50% cast time reduction = 2x faster nukes

 

AND (to the recast reduction) is ...
50% casting speed reduction cap...

 

Does the nuker skill to reduce cooldown go over the cap or is that useless after cap from items?

 

Useless

 

I just found the mastery skills go over 50% Cap.

 

That's a flat value reduction, not %