I'd like to add my 2 cents: how would proximity chat work? In the game's Settings you have an option to completely disable Proximity Chat to avoid accidentally turning it on. If a player has proximity chat enabled in the Settings, they can use it through 2 functions assigned to a single button. - Hold the button to switch between listening to Fireteam chat and proximity chat. This is the function that enables Proximity Chat. - Press the button to switch between talking in Fireteam chat only and proximity chat. This way you can hear everything in the proximity chat but only talk to your Fireteam if you choose to. I think having these two functions would be simple enough and allow the amount of flexibility needed so the proximity chat works well