You are pretty much where you want to be imo.....Next res change go with RO water
and I'd do....

CalMAg 300.....i would leave this number all the way through your grow

PB Bloom 600 (top out at 700ppm)
LK Same as whatever you are using (top out at 7ml/gal)
Sweet....same as whatever you are using (same as LK) and then if no problems.....go to the max. But if you encounter the same issue (big drop in numbers...) I probably wouldn't RAISE nutes....just change res more often to keep a balance.

You are pretty much looking at what I flower my plants with....the only change I make is increase the bloom nutes by about 100ppm when I switch over the to bloom booster.....ends up at 700... ending with about 1350 ish....I don't really go above that.

How high are you thinking you want to go cause after that you are on your own....

If you can change your rez to fresh stuff tomorrow I would....clean slate to watch plants from if possible and if trends continue just make the CalMAg part of your regular nutes. I think this is a good idea to do very soon because they seem to have stopped sucking everything down. What if they stopped sucking things down because they ran out of something?? ....We don't really know and we don't want that which is why I suggest a fresh start tomorrow. If you get the same trend tomorrow (big drop right away then nothing)...I'd probably change the rez again until I got an even trend going. Make sense?

MVP...you can't rush these girls.....they will need time to recover. All you can do here is play defense and watch them carefully. They will take some extra time and I don't think there is any way around that. I think if you try to push too much too fast you will burn them.....not worth that worry after all this work you've done.

Your turn to wait and see....