Let's say Xi Jinping wants to make the Han Chinese the masterrace, focusing on fixing the two things they're often disparaged for:
>height
>penis size

Would it be a feasible option to make a significant impact if they chose to? How hard would it be?
I suppose testosterone treatment for penis size during childhood and HGH during puberty for height are the main options.
Or are we close to more complex DNA engineering where we can safely "improve" these aspects?