Fox Farm trio question ?

Does it make a big difference to add the grow big when flowering or is it pretty much the same just using tiger and big bloom?

I haven't made it to flower yet, flipping this coming Monday, but I've been following FF's feeding schedule and plan to keep going with it. I believe the dose of Grow Big during flower is to give a boost in Nitrogen for continuing healthy green growth. I'm a noob so let's see what some more experienced users say.

Plants use nitrogen in flowering.