big bloom is not a stand alone fert. all he asked was if it can be used during veg. it is actually DESIGNED to be used throughout the grow. so yes, you are missing something.
u can use alot of different shit during different stages u dont always gotta follow the directions..as long as your NPK isnt all out of whack you will be fine..i know some dude who uses big bud during veg and flower and the bottle says to use it weeks 2-5 of flower and i also know a dude who uses a ripener product the whole time during flowering and gets some rock solid nugs