I have read a lot of guides and they always tell you to Not delay mirror images for Icy Veins,but never seen the answer of this question:
Is it a Dps increase if you delay your icy veins by 1 min to sync it with your 3rd miror images ? If you still dont get it it is like this: 00.00-cast IV + MI.... 02.00-cast MI..... 04.00-cast IV +MI... OR
00.00-cast IV+ MI....02.00-cast MI...03.00-cast IV...04.00-cast MI..06.00-cast IV+MI
PS: if the fight is longer than 6 min..?
Delay your mirror images if you will not lose a cast.
In a 4 min fight you can get 2 casts (0,2 v 0,3) so delay the second MI.
In a 5 min fight you can get 3 casts (0,2,4), if you delay you can only get 2 MI so don't delay).
In a 6 min fight you can get 3 casts (0,2,4 v 0,3,5), therefore we delay the second MI.
In a 7 min fight we get 4 casts (0,2,4,6), we don't delay MI because we will lose a cast.
This pattern continues, It would be more of a dps loss to delay a MI and not get it off rather then use it on CD so unless you know the fight length use it on CD.
I think what Sheridanjohn try to mean is this: since MI has 2 mins CD and IV has 3 min CD you only delay if you can take advance of both and you won't lost them
In 4 mins fights: you can have maximum of 2 MI (at 0 and 2) and max of 2 IV ( at 0 and 3) so delay MI and cast both of them at: 0 and 3 mins mark.
In 5 mins fights: you can have maximum of 3 MI ( at 0,2 and 4) and max of 2 IV ( at 0 and 3) so delay IV and cast like this: 0 MI+IV, 2 MI , 3 nothing, 4 MI+IV