Edit: with the new UI to texture features being added allowing for detailed pip mfd/displays for weapon control seats in vehicles, a key remaining ability will be correctly controlling aim sensativity for the vehicles turrets when viewing the pip screen in first person. We'll need a way to control the turrets aim sensativity based on the fov of the pip screen/camera and not the players view.
Currently, there is no way to decrease the sensitivity of the player's aim sensitivity while ADS via script.
The in-game mouse sensitivity of scopes is based on the gameworld's rendered FOV, thus a dual render scope optic that's zoomed still moves at a very rapid sensitivity preventing accurate aim of any kind.
Adding this feature would allow for dual render scopes to be aimed correctly when at higher magnifications, this is the only major issue remaining that prevents, highly sought-after, dual render scopes from being added by modders. This also will allow for weapon turrets to be aimed properly from the pip mfd display.