If I transplant 3 times in a 5-6 week veg period , FF Grow Big pointless?

I've been readin that after transplanting from 16oz(transplant after 2 weeks) cups to bigger pot, I don't add nutes for 2 weeks(transplanting into ffof) so that would put my lady at 4 weeks of veg, then I would transplant again into a final pot (5 gal) meaning I wouldn't have to feed for another 2 weeks, which would put me at 6 weeks veg total. I this I the case, then would I even use FF Grow Big at all? Or did I buy it as a paper weight??

I run FFOF as well and don't feed any veg nutes until needed. which is in about week 5 or 6 from uppotting from solo cups to 1.5 gal, to 3 gal.