I have more height avalaible. I harvest 1ft tall plants because its what mi lighting setup aloow to do sucessfully. Taller plants dont give me more buds yield, just more leaves and stems.

With 2ft avalaible is more than enough. No problem with that. Of course, always you work with clones. Other case, probably you will need to LST (train your plants) or doing a scrog.

I almost not do any veg. Just what clones need to root fine, some days at 18/6.

Short day schedules (as 6/12) helps reducing stretch and shortening the transition to bloom period, when happen most stretch. Keeping difference between night and day temperatures small helps a lot to. Never over 5ºC (about 10F) and preferably less. Using that, you may be able to fit plants from seeds in that space, provided the genetic not tend to stretch (choose indica dominant strains).

But LST is often a simpler way of doing it when working with seeds.