From a development standpoint it would be incredible if we could get a hook within Unity for certain keybinds to be pressed, specifically in a sense that you could detect if the nightvision button was pressed for example, or the aim button, but for this to also apply to new / special keybinds for vests, masks, hats etc etc.
As this would allow for more functionality with clothing, such as helmets with the ability to move a visor up / down, instead of the current bypass it being a pair of goggles that hook into the headlamp activation.
And one additional possibility to give a .dat tag for certain pieces of clothing to be rendered in first person if the tag or string is present, this would allow for say, a face mask to slightly cover the lower parts of the screen.
Adding in these functionalities would prove useful to a lot of developers and would positively affect the current modding community.