Build Up and Assassins Mark Proc

[Yomo Kimyata]

So, the proc has a ?4?% chance to reset Build Up.  Cool, cool, but I was wondering if anyone has taken a deep (I.e. mathy) look into this?  Specifically, are you best served by hitting Build Up every single time it pops up, or does the activation/animation time of the power throw you off from your attack chain too much DPS wise?  I’ll welcome anecdotal as well as hard evidence.  I don’t quite understand the listing in city of data, but I’m assuming the proc rate isn’t a hard 4% per power activated.  I don’t play stalkers enough to have any confident answers for myself