Let's say you have two plants of same size and strain in soil. Both at 6" (first alternating nodes)
Put one in the flower room, one you keep in veg until first signs of sex appear, then add it to the flower room.
Which one will finish faster?
Which will be the larger healthier plant come harvest?
Which will grow faster and be less susceptible to stress?
The one with a longer (proper) veg time.

Don't sell yourself short.