Most ferts have molasses anyways but the extra you put in really helps. I personally think it is only worth it after the 3rd to 6th week of flowering. You want it to fatten up the buds not the leaves and stalk so I wouldn't advise putting in veg. Thats why in only 98% flowering boosters have the scent of molasses in it and none in veg ferts. The sugar is almost like creatine for humans, it fattens you up cuz the fat turns to muscle(when you workout). in this case the sugar for the plants help break down stuff etc... so your bud is working hard to gain weight and produce buds and the sugar helps it.

I thnk adding sugar during veg is not worth the extra hassle.

I use 2tbsp per gallon myself.