Originally Posted by
Jessicka
I don't understand what you're saying.
Your UA and Contagion up time is limited by Shard accumulation. You want to maximise Contagion up time by maximising your UA up time, which means not stacking UA unless you absolutely have to.
Secondly, if you do spam UA like a nuke, then save up 5 more Shards to spray in some kind of burn phase like old-school Chaos Bolts, you will very probably have capped Compounding Horror stacks and therefore lost many of them. This is a significant DPS loss. Again, this is resolved by spacing your UA casts so as not to cap CH stacks.
There is nothing to be gained by stacking UA unless you have an over-abundant income of Shards, which typically only happens from spreading Agony around - with which you would probably normally want to spread UAs around rather than stack them into one target. Or if you have a very specific burn phase in an encounter for which you were saving resources because the thing absolutely has to die within a small window.
The amount of damage from 5x UA is exactly the same whether they're stacked or consecutively cast, unless they're cast within a short term +damage period like a trinket proc.