Micro Grow - Plants Different Age When To Veg

Ok I have encountered a slight problem of sorts.

Firstly I only have one grow space and so I cannot have a vegging/flowering room separate, I have one plant from bag seed around 20-30 days old which had a stressful time so is not the usual size of a 20 day plant still around 15-20cm in height, a plant about 5cm just growing its second set of leaves and a little baby just poked its head above soil.

Now due to only having one grow space what is the minimum recommended time to veg these younger plants before switching to 12/12, if say I was to switch to 12/12 in a week or 2 would there be any adverse effects on the smaller plants??? I know yield will be effected by vegging time but I would more like to flower all at the same thus allowing me to plan better and start all plants at same time to keep them in sync

12/12 all plants Seed to Harvest.. works very well. Any stage plant 12/12 it will veg until flower just fine under the same light

In general, plants will flower out fine regardless of how much veg time. Back in the day, we used to tell people they couldn't flower until you saw alternating nodes, but I'm sure we've all learned through experience since then that you can flower, as stated above, even from germination.

As you know, yield will be effected.

Look into training your bigger one with LST supercropping and growing the other two unmolested, this will help minimize the size difference, make it easier to get them to a uniform height under your light.