Hello friend, I have had several variations in genetics from Dutch breeders. Pulling out at pre-flowering and early flowering, does not always depend on the genetics of the plant. The composition of your nutrient solution, and the intensity of the light plays a big role.
I've come across both midget variations of Jack (+50% on preflower) and "massive bastards" of Jack (+200% on preflower and early flower)
Monitor plant nutrition, growth dynamics. Control with LST and HST techniques. Hope I was able to help, good luck!