heh,
I was sort of looking into finding answers to similar questions.. and realize this is several months after the fact....but I could provide you with my past experiences if you'd like..?
I've supplemented the Fox Farm family-minus the granules- with Canna bloom boosters, pk-13, boost, cannazyme, and rhizotonic, as well as molasses, for several grows with fucking sweet results. I found that the FF nutes were just a fraction of what could really contribute to the growth of my plants in bloom cycle, by allowing their leaves and growth to quickly drop off in terms of vigor. The leaves all browned, and that was that. Now, I have healthy plants that are green till I pick em, dense and shit buds, and an average of 2 oz. gain on my yield per plant.
Sometimes it's good to splurge a bit on them ferts.