It is indeed a server rule. 10 minute cooldown when your helicopter gets shot down so it would still apply.
However, fixing how helicopters fire their weapons and their usage during war is what this suggestion is for and you have yet to offer a valid counter argument. Flying the attack heli is not an easy feat, let alone firing your rockets accurately, avoiding enemy rockets, and giving your gunner a stable shot. And we tested recently and found that the gunners seat gun is horribly inaccurate, even stable and close to the enemy. So as you said it would be "super cancerous," I can 100% assure you that it won't be for the guys on the ground and that you have no idea what you're talking about