Anything I need to do the last 2 weeks of veg with dwc?

I'm nearing the end of my veg (this is my 1st grow btw) . I'm growing in a bubble bucket . I have three plants in one bucket one isn't doing well, I realize that three in one 5g bucket isn't optimal, but I haven't culled it yet incase I have some males. I am just wondering if there is something that I should start doing at this time that may help yield, I'm thinking about scog. But not sure as I don't know if I have females yet or not. I also have a couple seedlings, should I just put them all on a 12/12 schedule? I'm kinda torn on this.
I started with bag seed and those are the three larger plants that are about 12" tall. My buddy got me a couple good seeds and they all have sprouted. So I have three 12" (bag seed)plants in one 5g dwc. 1 (good) seedling in another 5g dwc. I have 2 more (good) seedlings in jiffy peat pellets. I have one more 5g dwc setup on the way. I only have one closet area to grow in, I have a 400w mh/hps, a 20w red led and a 55w/250w cfl. I have decent timers, a fan, and ozone gen. No air intake exhaust setup besides opening closet door.

I guess I have two big questions

1: should I be doing anything with the big plants bin the couple weeks before switching to a 12/12 light schedule ?

2: what should I do with the seedlings? Let them grow more and then the bag seed plants will be huge or start flowering cycle based on the larger (bag seed) plants?
I can't really seperate the different sized plants at this point.