Thor I had a similar idea to what your doing with a longer veg cycle. I only have limited space and time to care for plants everyday though so am mostly automated and just growing small for personal use at the moment and for some time to come.
The benefits of extended veg period is really just to bulk up your plants, and is entirely dependent on the space you have, with small grow rooms there is really no point to veg for a longer period of time as you would just end up trimming a lot in my view, but if your working with a large tent space (which is what I wanted to do in the future when I buy my own house), I could totally see the benefit of this.
Im growing under an 80w cfl 2 27w cfl for part of the veg cycle (germinated on the 8th and the 14th and moved into DWC on the 14th and the 18th while they were still a bit small), I just topped 2 and am waiting for the others to grow bit bigger also before I move them into my 400w grow space. I have a scrog screen set about 8 inches above the pots and plan to fill the screen for 2-3 weeks before switching to 12/12. So far its all going well and only had some heat issues when the temps spiked up to 95-100 outside, had to change the light cycle, put some ice packs by the fan to blow cool air into space and general headache.
Its my plan to clone the white widow x skunk#1, sage n sour, and northern lights, really depends on how the plants perform.. I have like 5 strains at the moment in my system but I just don't think the space will allow for it and a few are really slow in veg so far comparative to others so I probably will end up pulling them and possibly transplanting to soil and throwing outside, I wont be concerned overly if they take or not.
Under my 400w Im hoping to get about 3-4 ounces, but we will see, got to get them through veg, flower and summer heat.