Do root systems basicly quit growing (expanding); during the flower cycle? Soil grows ONLY.

Asking?: does the root system mostly form during the veg cycle?...which would mean, it be a waste of time to transplant to a larger pot...after flowering cycle has started?

Opinions requested. Bottomline, veg longer, more roots=bigger plants?...more yield?
Dutch Pimp Reviewed by Dutch Pimp on . Should I Flower or Wait? These are recent pics, My babies are 31 days old, and growing under 24/0 600w plus a 175w Mh lights. 10 are w/w, 5 are mystery seed that came with the w/w. 3 of those are sativa dominant looking and acting to me. I have been doing LST to keep the canopy around 6" above the soil. I fed them 24/20/20 nutes in 5.5ph water last night. The main stems are 3/8" to 1/2" diameter As you can see I am running out of horizontal space. Rating: 5