I really think the battlefield franchise didnt use this mechanic as much as it should
The tracer gun had only 1 bullet in the chamber and a long reload, once it hits a vehicle, your RPG follows the vehicle until the missile explodes or it reaches the vehicle, hitting it.
It was a good counter to the fast helis in the game that, otherwise, would dominate lobbies, and it required skill and had a learning curve kinda like the RPG
I think this would be the best solution for people who want a better way to counter helis in this game, its not a cheap shot ,it requires skill and planning, and it could be balanced to not be abused :)
Just my 2cents on a mechanic that was already proven effective in other game
Then come the question, do you make it a indestructible object. Or it's weak to explosive? Tandem? (repairable maybe with squad point?)