Interesting that (apparently) many in the French Army have just discovered the utility of a rail :
“In Ménaka, at the beginning of December, we carried out a search operation of houses during the night. The HK416 allowed us to place complementary accessories such as a lamp on a rail fastening system. We were much more efficient than we could have been with a FAMAS. Before, we progress in operation lamps by hand or pressed against the rifle. This capacity changes everything. ”
https://www.thefirearmblog.com/blog/2019/03/05/heckler-koch-416f-deployed-in-sahel/