Don't defoliate!
ALL of the plants energy to grow and thrive is made by/in the leaves.
Less leaves = less energy being made = less potential growth..............it is that simple.
Besides, light spectra we humans can not see will actually penetrate upper leaves and strike so called "shaded" leaves underneath, making defoilation pointless.
Defoliating such a small plant would severely reduce its ability to make enough energy to grow as fast and big as possible.