Give them a half dose of Big Bud a week before flipping then the other half at the flip. You want all that goodness in there for the huge growth spurt that happens during the stretch. Bud Candy later on.
I just typed the following yesterday when I noticed the change in the 3-part formulation after someone talked about using the AN jungle juice on another forum. How I never noticed in 5 years is beyond me but I need to make changes.
AN can be used in soil grows just fine and contrary to bro-science expounders using hydro nutes in soil does not kill the beneficials. If your soil is already rich in organic nutrients you have to be careful or you’ll easily overfeed the plants and end up with nute burn or even worse, Toxic Salts Buildup. TSB can happen with just rich organic grows too especially if using hard tap water with it as the minerals in tap water are salts too and add to the overload.
I only use the 3-part base and Big Bud. Any old CalMag will do and some epsom salts. All that other stuff is not needed and way too expensive for my wallet. I’d use them if they were free tho. 
I’ve been using AN 3-part for 20 years. I bought gal jugs about 5 years ago and just now noticed that the N-P-K ratios have changed but I’ve been using it just like the older stuff that has the same ratios as the Jungle Juice and the GH 3-part. This may explain some of the problems I’ve seen in flowering especially when I switch to Lucas Formula feeding after the stretch. I have 1L bottles of the older pre-pH Perfect 3-part and dug them out to check.
Old AN, JJ and GH are Grow - 2-1-6, Micro - 5-0-1, Bloom - 2-5-4
This 5 yo AN 3-part is Grow - 1-0-4, Micro - 2-0-0, Bloom - 1-3-4
Totally throws thing off to what I had become so accustomed to. I’m going to have to sit down and reformulate some of my mixes to be feeding each nute at the same ratios I was before. Much more diluted now too. With less than half the N as before it throws the Lucas feeding way off. No wonder the old leaves yellow out so fast and early.
I also have some REMO nutes from winning a 7 - 250ml bottle kit in a raffle at a hydro store I deal with and their ratios are different again.
G - 2-3-5
M - 3-0-1
B - 1-4-7
Flip a coin I guess or dust off the math books and nail it down.
