Next time you are on cycle try three weeks of 10-15 reps for some exercises and 15-20 for heavy compound leg exercises like leg press and see what happens. Of course, progressive overload, keep pushing that weight heavier once you hit your target reps, keep adding reps when you can't add weight, and so on and so forth.
You might find it works for you. If not, you can always start the fourth week with a slightly heavier weight to get you down under 12 reps again. At least you will know.
You might find that you grow quickly just because it is so different from how you have done training for your entire life. It will be like a brand new stimulus for your body. It is a very uncomfortable stimulus, though. Fair warning. Reps 17, 18, and 19 on the leg press are very uncomfortable if you are using heavy weight. And you really, really, won't want to do the next set. Push through. You may find you love what you see in the mirror a month later.