Critical+ when to flower?

I'm on day 22 of veg with these critical+ plants. I may have mixed a white widow x big bud in by mistake because one plant looks different. I have topped 2 and FIM'ed 2 once. My grow space is only 4x4' in a 4x8 grow room. I plan to veg for another 4-5 weeks but don't know if the plants will out grow the space during the flowering stage.
I was planning to let the new tops get about 5 nodes then sex and super crop them before lowering the SOG net a week or 2 before flowering.
Or should I flower sooner?

Also can anyone also see the one different plant?

Fill in that screen 70% before flowering
Jmo