The cooldown ini provides a cooldown of 2 minutes after every mission in which you cannot get a hit.

The unlockable mode ini turns the mission into an unlockable, in order to unlock it, you need to do the Minigun ammu nation challenge and leave the area, you will receive a message.

The unlockable mode and cooldown will give you both things.

Just drag and drop your selected ini into the Javelin V folder