What haste level are we supposed to aim for using Expedient corruptions before we can get either Gushing Wounds or Ineffable Truth 1 as a Destruction warlock?
And is three IT 1 necessary to play the Eradication/Internal Combustion Build or can we just keep stacking Expedients to get more haste to get away with it?
I’m slightly confused, and would appreciate some clarification.
Mostly 5-6 expedients should be enough to get u over the 4 thousand mark, which is when i’v seen people shift to eradication/internal combustion or IT or gushing wounds. The Vita trinket would be a nice addition. Also, sockets take care of a huge chunk. But since you’re already done with all 15’s… up to u how much more u want to grind 
You dont get gushing wounds or IT. You get more expedients. As of right now you can have expedient 3 on all your pieces and be sitting at 57 corruption.
Expedient 3 vendor is up as well.
You don’t need IT to play erad/ic build. There is no specific haste break point that i’m aware of to play the build but i reckon around 3-4 pieces of expedient 3 should be good.
I am sitting at 96% expedient total with a base haste of 74% (76% with food).
I want more.
I stopped feeling a difference after I hit around 4200 haste. Could be because I didn’t enjoy Erad/IC which is a little more haste-hungry. Gonna try IT this week… two rank 1’s & one rank 2 (I know the 2 is bad but I’m out of pieces). Gonna keep one gushing wounds to help proc VoP & IT. Should be fun.
if you are running the IT build it’d be 6 expedient 3s and 3 IT 1s, which as of right now is like 36 corruption, thats what i run, when it works it goes big.
otherwise you can just stack expedients to your heart’s content, and the Erad/IC build is based on expedients, IT has nothing to do with it.