How about a "Hold Fire"-Option for Autonomous HMG and GMG?
example; you want to place an autonomous HMG on east side of an hostile compund u wanna attack, but dont want it to fire directly. You first want to move on with your team on the west side for the attack. Then you can switch to "Engage at will" for the autonomous so that the enemy is fired from east and also mainly pays attention to that direction. Meanwhile you and your team can engage the compund from west.