If everything goes ok peripheral nerve cells can grow if the "tunnels" they are in (Schwann cells) remain sufficiently, because these serve as "conductors" for nerves cut in an accident, if properly positioned by the surgeon, for nerves to grow AND reconnect themselves.
It's a very good question for the forum to know if stretching of LL at the "right speed" actually causes nerves to also really grow, like that, or just stretch by brut force.
Anedoctally, if that is not the case, everyone may ask "why not cut the nerves to avoid problems of purely stretching nerves" (and then of course reconnect the Schwan cells "tunnels"). I would answer: because it's too dangerous?
But it would be really good if peripheral nerves grow when stretched. I know this partially occurs with muscle when bone is lenghtened.
Maybe Dr. Assayag can help. It's not easy just in a Google search.
New discoveries prove that nerve cells, including in the central nervous system, can even divide (not grow), in some conditions. But unfortunately I don't see any means to apply this clinically in the very near future.