Just my opinion but Friendly Fire ON is not a good idea. I prefer not killing my teammates by accident and not being killed by them either. If I wanted real world simulation, I would've joined the army. I want to napalm or machine-gun the enemy indiscriminately and not worry about my teammates having super powers of not getting killed by my bombs. I remember playing in other servers where FF is ON and it sucked and wanted me to run back to Hello server. Another thing other servers get wrong is by preventing seats-witching. Of course those rules are created by admins who suck at seat-switching anyways, and then get mad when they get fragged by
Im not gonna make it a federal case, thou Im convinced it would make people think twice with tubes, not to mention other explosive ordinances spammed on flags. PS (Im in the army, and friendly fire is always ON.)
The main idea is, no way we can enable damage only for LAW or M79. It will also affect other things, like napalm bombs, etc etc. There would be a lot of teamkills here and there every minute, and admins won't even be able to tell if it was intentional or not. It has so many downsides, that FF has never been set up as a constant feature, players could try it only in failed trials. Considering the low number of players nowadays, it would be especially critical for gaming experience.