I mean, you guys assume that when putting Tsuji's hair into a balding scalp/area, it won't grow, because it starts acting as a balding follicle due to the tissue being placed in.
We do know that when you plant a scalp hair follicle onto your arm, it will start to bald at some point, and we do know that hair transplant's last for a long time. Consider the fact that we are talking here about an endless supply. The science is there, if it won't work on humans,... that'll be very weird. However, we are indeed far away from such interventions.