You're wrong, there is no evedience proved that Testosterone can accelerate the epiphyseal bone closure process, if used or excreted without converting to Estrogen
Testosterone by it self do not promote this process, but at least Testosterone stimulates growth of cartilage and bone at epiphyseal which gives pubertal growth spurt while the converted Estrogen from Testosterone stimulates closure of epiphyseal plate and thus stops pubertal growth spurt